Rolling diaphragm pump

A rolling diaphragm pump that can inhibit an increase in cost with a simple configuration is provided. A rolling diaphragm pump 1 includes: a housing 2; a piston 3 disposed so as to be slidable relative to an inner peripheral surface of the housing 2 and reciprocatable in an axial direction; a rolling diaphragm 4 having a movable portion 41 disposed at one end portion in the axial direction of the piston 3 and reciprocatable together with the piston 3, a fixed portion 42 fixed to the housing 2, and a flexible connecting portion 43 connecting the movable portion 41 and the fixed portion 42 to each other; a pump chamber 5 defined by the rolling diaphragm 4 at one side in the axial direction within the housing 2 and into and from which a transport fluid is sucked and discharged by changing a volume of an interior of the pump chamber 5 by deformation of the connecting portion 43 due to reciprocation of the piston 3; and a working fluid chamber 6 defined by another end portion in the axial direction of the piston 3 at another side in the axial direction within the housing 2 and into and from which a working fluid is supplied and discharged, thereby causing the piston 3 to reciprocate.