To provide an oil force feed device capable of easily changing a manual method and a driving method.

A shell body 1 is provided, and an upper lid 11 is arranged on the shell body 1. A manual mechanism 2 and an air-driven suction mechanism 3 are arranged on the upper lid 11, and the manual mechanism 2 has a body 21. The body 21 is sealed by the upper lid 11 and a lower lid 12. A piston is arranged inside the body 21, and the piston has a handle 24 projecting from the upper lid 11. A storage space 13 is arranged outside the body 21 inside of the shell body 1. The upper lid 11 also has a suction hole communicating with the storage space 13. Since a closing device 34 capable of switching the air-driven suction mechanism 3 and the manual mechanism 2 is arranged on the upper lid 11, when changing an oil force feed method, there is no need to change or take out a part so that the oil force feed method can be quickly changed, and is convenient.