To provide a bellows type of liquid feeding pump furnishing the damage preventive function of a bellows.

In this liquid feeding pump 5A of this execution type, a bellows 507 is fixed to a bellows plate 502 in which a suction port 504 and an exhaust port 505 are formed, the expansion and the contraction of the bellows 507 are carried out by an air cylinder 524, the bellows 507 is compressed by the lowest pressure of the air cylinder 524 under the constant driving and control of a pulse motor 521, when a chemical is being discharged, and a structure to discharge and feed a specific amount of chemical from the discharge port 505 at a specific discharge speed is applied. The connection of the pulse motor 521 and the air cylinder 524 is carried out by a ball nut 517, and the drive and the contrl of both members are carried out by a driving program assembled in a drive control device 525.