PURPOSE: To promote the simplification of construction of a pump, by providing at least one control valve, which forms a part of a suction passage, in a delivery passage of the multiple reciprocating pump and applying the delivery pressure to act on the valve to be bypassed to a side of the suction passage so as to regulate the pressure of fluid.

CONSTITUTION: A cylinder head of each cylinder 5 provides a valve seat 91, having in its center a suction hole 91a and in its outside annularly a delivery hole 91b, and mounts a cylinder cover 8 parallelly having delivery passages 8b and a suction passage 8a from a side of the cylinder 5. Then a cylindrical control valve 11 is provided to be opposed by a spring 12 in at least one of the suction holes 91a. The inside of this control valve 11 is communicated with the suction passage 8a, while the outside of said valve has a pressure receiving surface 11a which receives the pressure of liquid in the delivery passage 8b. The pressure acting on this pressure receiving surface 11a and the action of the spring 12 are applied so as to actuate the control valve 11.