PURPOSE: To eliminate various malfunctions caused by pulsation by providing a plurality of squeeze-type pumps in parallel and shifting respective phases by a specific amount in a method for force-feeding concrete or the like in squeeze pumps.

CONSTITUTION: Two squeeze-type pumps 1, 3 operated by one driving motor are placed in parallel. A hopper 9 houses concrete or the like and suction pipes 13, 13 split from a suction pipe 11 into two are connected to intake ports of the squeeze-type pumps 1, 3. Discharge pipes 15, 15 are connected to discharge ports of the squeeze-type pumps 1, 3 to be assembled in a pipe 17. If phases of the squeeze-type pumps 1, 3 are set by 180°, the respective changes in pressure overlap with each other so that amplitude and frequency of pulsation peculiar to a squeeze-type pump can be reduced thereby eliminating various malfunctions caused by the pulsation.