To provide a self-suction type to automatically stop a pump when an amount of liquid injected in a container attains a given value, prevent the occurrence of an overflow due to an injection surplus, and perform safe and high-efficient injection of fuel liquid, such as light oil, in the container.

A suction hose 3 and a discharge hose 5 are connected to the suction opening 2 and the discharge opening 4, respectively, of a motor-drive pump 1, and liquid detecting sensors 6 and 7 are situated in the tip parts of the suction hose 3 and the discharge hose 5, respectively. The liquid detecting sensor 6 in the suction hose 3 starts the motor-drive pump 1 during detection of liquid and stops the motordriven pump 1 during non-detection of liquid. Further, the liquid detecting sensor 7 in the discharge hose 5 starts the motor- drive pump 1 during non-detection of liquid and stops the motor-driven pump 1 during detection of liquid. This operation automatically stops the motor-driven pump 1 when an amount of liquid injected in a container attains a given value.