FLUID PUMP

PROBLEM TO BE SOLVED: To achieve reduction of the number of parts, compactness, and light weight while avoiding strength deterioration of a pump main body in a hydraulic pump having a diaphragm between the pump main body and a cover, and a relief valve between an intake chamber and a discharge chamber. SOLUTION: A pump main body 35 is provided with a pump main body main part 35a, an intake part side protruded part 35b protruded from the pump main body main part 35a, a discharge side protruded part 35c protruded from the pump main body main part 35a, and a communication wall part 35d connecting the intake side protruded part 35b to the discharge side protruded part 35c and connected to the pump main body main part 35a, a part including the intake side protruded part 35b forms intake chambers 52, 53 in the pump main body 35, a relief valve 63 is provided in the pump main body 35 at the part including the discharge side protruded part 35c, a discharge chamber 61 and a return chamber 62 connected to the discharge chamber 61 through the relief valve 63, and relief passages 70 communicating the return chamber 62 with the intake chamber 52, 53 are formed in the connection wall part 35d.