The embodiment of the invention discloses a money box, an automatic teller machine and a money box state monitoring method. The body of the money box is a box body. The box body is internally and flexibly provided with a money push plate which bears money to translate upwardly and downwardly and also provided with sensors which are used for detecting whether the box is empty. An inclined angle, which is greater than 0 and less than or equal to 45 degrees, is formed between a detection surface corresponding to the sensors and a length direction of the money push plate. The corresponding short side length of the detection surface is less than or equal to length of paper money stored in the box body. The sensors are arranged in the box body, the preset angle is formed between the detection surface of the sensors and the length direction of the money push plate in an inclined way, and the corresponding short side length of the detection surface is less than or equal to length of paper money stored in the box body so that the empty state of the money box can be accurately detected, and the situations of missed detection and false alarm can be avoided; and the money box also has the characteristics of being simple in structure and low in cost.