To prevent the residence of a liquid caming into an air pipe accompanying exhaust operation by providing in an air exhaust pipe, an operation value made to swing freely to either stop or release air flow.

A liquid to be injected into a bottle fills a tank 1. A bottle A into which the liquid is to be injected in this condition is automatically raised by other suitable equipment. When the bottle is being raised, the inside 3 of the mount part of the bottle A is pushed up from the bottom opposing the pressure of a coil spring 4. As a result, the inner cylinder 3 goes up creating a gap between the bottom of the inner cylinder 3 and the valve seat 6 in the air exhaust pipe 7. Simultaneously, a window 9 in the inner cylinder 3 also goes up and is exposed in the tank 1. Because of this, the liquid in the tank 1 comes into the inner cylinder 3 from the window 9 to fill the bottle A passing between the bottom of the inner cylinder 3 and the valve seat 6. Simultaneously with the injection operation, the air in the bottle A goes up in the air exhaust pipe 7, pushes up an operation valve 8 and is discharged from the top end of the air exhaust pipe 7 to the outside. Also in many cases, the liquid went up with the air within the air exhaust pipe 7 is returned to the tank 1.