diff --git a/README.md b/README.md
index 1298187..c2d4e4f 100644
--- a/README.md
+++ b/README.md
@@ -35,7 +35,7 @@ This library allows you to transfrom automatically Express.js _req.query_ into T
 
 ## How it works?
 
-![](typeorm-express-pipeline.png)
+![](https://raw.githubusercontent.com/rjlopezdev/typeorm-express-query-builder/master/typeorm-express-pipeline.png)
 
 
 ## Usage
@@ -118,6 +118,11 @@ __gte__ | Return entries with value greater than or equal to provided | `foo__gt
 __in__ | Return entries that match with values in list | `foo__in=admin,common`
 __between__ | Return entries in range | `foo__between=1,27`
 
+**Notice**: you can use negative logic prefixing lookup with `__not`.
+
+*Example:*
+`foo__not__contains=value`
+
 ## Options
 
 | Option | Default | Behaviour | Example |
diff --git a/package.json b/package.json
index 8a82262..2fc7e24 100644
--- a/package.json
+++ b/package.json
@@ -1,6 +1,6 @@
 {
   "name": "typeorm-express-query-builder",
-  "version": "1.0.1",
+  "version": "1.1.1",
   "description": "Easily transform an Express req.query into TypeORM query",
   "main": "index.js",
   "scripts": {
diff --git a/src/field-filter.ts b/src/field-filter.ts
index 919c3ad..32ee055 100644
--- a/src/field-filter.ts
+++ b/src/field-filter.ts
@@ -1,11 +1,14 @@
 import { AbstractFilter } from './filter';
 import { LookupFilter } from './lookup.enum';
-import { Like, IsNull, LessThan, LessThanOrEqual, MoreThan, MoreThanOrEqual, In, Between } from 'typeorm';
+import { Like, IsNull, LessThan, LessThanOrEqual, MoreThan, MoreThanOrEqual, In, Between, Not } from 'typeorm';
 
 export class FieldFilter extends AbstractFilter {
 
-  constructor(query: any, prop: string, lookup: LookupFilter, value: string) {
+  private notOperator: boolean;
+
+  constructor(query: any, prop: string, lookup: LookupFilter, value: string, notOperator: boolean = false) {
     super(query, prop, lookup, value);
+    this.notOperator = notOperator;
   }
 
   public buildQuery() {
@@ -48,6 +51,9 @@ export class FieldFilter extends AbstractFilter {
         queryToAdd = { [this.prop]: Between(+rangeValues[0], +rangeValues[1]) };
         break;
     }
+    if(this.notOperator) {
+      queryToAdd[this.prop] = Not(queryToAdd[this.prop]);
+    }
     this.query['where'] = {
       ...this.query['where'],
       ...queryToAdd
diff --git a/src/filter-factory.ts b/src/filter-factory.ts
index 0a3d69c..089ac13 100644
--- a/src/filter-factory.ts
+++ b/src/filter-factory.ts
@@ -7,10 +7,11 @@ export class FilterFactory {
   public get(query: any, key: string, value: string): AbstractFilter {
     if (this.isFieldFilter(key)) {
       const field = key.split(LookupDelimiter.LOOKUP_DELIMITER)[0];
+      const notQuery = key.includes(`${LookupDelimiter.LOOKUP_DELIMITER}${LookupFilter.NOT}`);
       const lookup = key.includes(LookupDelimiter.LOOKUP_DELIMITER)
-        ? key.split(LookupDelimiter.LOOKUP_DELIMITER)[1] as LookupFilter
+        ? key.split(LookupDelimiter.LOOKUP_DELIMITER)[notQuery ? 2 : 1] as LookupFilter
         : LookupFilter.EXACT;
-      return new FieldFilter(query, field, lookup, value);
+      return new FieldFilter(query, field, lookup, value, notQuery);
     }
   }
 
diff --git a/src/lookup.enum.ts b/src/lookup.enum.ts
index f65b2dc..03ac090 100644
--- a/src/lookup.enum.ts
+++ b/src/lookup.enum.ts
@@ -9,7 +9,8 @@ export enum LookupFilter {
   STARTS_WITH = 'startswith',
   ENDS_WITH = 'endswith',
   IN = 'in',
-  BETWEEN = 'between'
+  BETWEEN = 'between',
+  NOT = 'not',
 }
 
 export enum LookupDelimiter {
diff --git a/test/unit/field-filter.spec.ts b/test/unit/field-filter.spec.ts
index 74ae710..3180944 100644
--- a/test/unit/field-filter.spec.ts
+++ b/test/unit/field-filter.spec.ts
@@ -1,4 +1,4 @@
-import { Like, IsNull, MoreThan, MoreThanOrEqual, LessThanOrEqual, LessThan, Between, In } from 'typeorm';
+import { Like, IsNull, MoreThan, MoreThanOrEqual, LessThanOrEqual, LessThan, Between, In, Not } from 'typeorm';
 import { FieldFilter } from '../../src/field-filter';
 import { LookupFilter } from '../../src/lookup.enum';
 
@@ -72,4 +72,10 @@ describe('Test FieldFilter #buildQuery', () => {
     expect(built['where']['name']).toEqual(In(['1', '2', '3', '4', 'foo']));
   });
 
+  it('should return a <not> filter', () => {
+    const fieldFilter = new FieldFilter(built, 'name', LookupFilter.EXACT, 'value', true);
+    fieldFilter.buildQuery();
+    expect(built['where']['name']).toEqual(Not('value'));
+  });
+
 });
diff --git a/test/unit/filter-factory.spec.ts b/test/unit/filter-factory.spec.ts
index 0c83463..25929bd 100644
--- a/test/unit/filter-factory.spec.ts
+++ b/test/unit/filter-factory.spec.ts
@@ -9,6 +9,18 @@ describe('Test FilterFactory #get', () => {
     const filter = factory.get({}, 'field', 'value');
     expect(filter).toBeInstanceOf(FieldFilter);
   });
+
+  it('should return an instance of FieldFilter with notOperator equals to true', () => {
+    const filter = factory.get({}, 'field__not', 'value') as any;
+    expect(filter).toBeInstanceOf(FieldFilter);
+    expect(filter.notOperator).toBeTruthy();
+  });
+
+  it('should return an instance of FieldFilter with notOperator equals to false', () => {
+    const filter = factory.get({}, 'field', 'value') as any;
+    expect(filter).toBeInstanceOf(FieldFilter);
+    expect(filter.notOperator).toBeFalsy();
+  });
 })