DIAPHRAGM PUMP

A diaphragm pump in which the lowering of the quantitativeness of the liquid transportation amount caused by the operation of a rolling diaphragm can be effectively suppressed is provided. A diaphragm pump 1 has: a housing 2; a piston 3; a shaft 4; a rolling diaphragm 5 which is configured so that a lid portion 35 reciprocally moves integrally with the piston; a driving device which can convert rotational movement of a motor section 30 to linear movement, and output the linear movement from an output axle 31 to the shaft; a guiding member 7; and a restricting mechanism 8. The guiding member is placed on another axial end side of an interior of the housing with respect to the piston, attached to the housing, and able to guide the shaft movably in the axial direction. The restricting member is disposed in the housing 2 and between the guiding member and the shaft, and able to restrict rotation of the shaft about the axis while allowing reciprocal movement in the axial direction.