A pump that is fitted to bosses protruding from a fitting target portion, the pump comprising: a housing (11, 19) in which a pump chamber that is a columnar space is defined, and a suction-side groove and a discharge-side groove are formed at a predetermined interval in a circumferential direction of a bottom of the pump chamber so as to be recessed in the bottom of the pump chamber; an outer rotor that is rotatably provided in the pump chamber and includes internal teeth formed at an inner peripheral side of the outer rotor; and an inner rotor that is provided inside the internal teeth, the inner rotor including external teeth that mesh with the internal teeth and are formed at an outer peripheral side of the inner rotor, wherein fitting portions that are fitted to the bosses are formed on an outer surface of the housing, wherein a protruding portion is formed so as to protrude from the surface of the housing on which the fitting portions are formed, and wherein a relief valve (16, 17, 18) is provided in the protruding portion, and the relief valve (16, 17, 18) discharges fluid from the discharge-side groove when pressure in the discharge-side groove is equal to or higher than predetermined pressure, wherein a suction-side relief recess is formed at a bottom of the suction-side groove, a discharge-side relief recess is formed at a bottom of the discharge-side groove, the protruding portion is a member that forms a relief flow passage communicating with the suction-side relief recess and the discharge-side relief recess, and the relief valve (16, 17, 18) includes the suction-side relief recess, the discharge-side relief recess, the relief flow passage, and a spool that closes or opens the relief flow passage, wherein the protruding portion overlaps with the bosses in a thickness direction, the protruding portion is formed between fitting holes on the surface of the housing, characterized in that the protruding portion is in the form of a block and protrudes in a thickness direction (z), in the surface of the housing, the position of the protruding portion in the plane direction is different from the positions at which the fitting portions are formed, and the positions of the suction-side relief recess and the discharge-side relief recess in the plane direction correspond to a position at which the protruding portion is formed. a housing (11, 19) in which a pump chamber that is a columnar space is defined, and a suction-side groove and a discharge-side groove are formed at a predetermined interval in a circumferential direction of a bottom of the pump chamber so as to be recessed in the bottom of the pump chamber; an outer rotor that is rotatably provided in the pump chamber and includes internal teeth formed at an inner peripheral side of the outer rotor; and an inner rotor that is provided inside the internal teeth, the inner rotor including external teeth that mesh with the internal teeth and are formed at an outer peripheral side of the inner rotor, wherein fitting portions that are fitted to the bosses are formed on an outer surface of the housing, wherein a protruding portion is formed so as to protrude from the surface of the housing on which the fitting portions are formed, and wherein a relief valve (16, 17, 18) is provided in the protruding portion, and the relief valve (16, 17, 18) discharges fluid from the discharge-side groove when pressure in the discharge-side groove is equal to or higher than predetermined pressure, wherein a suction-side relief recess is formed at a bottom of the suction-side groove, a discharge-side relief recess is formed at a bottom of the discharge-side groove, the protruding portion is a member that forms a relief flow passage communicating with the suction-side relief recess and the discharge-side relief recess, and the relief valve (16, 17, 18) includes the suction-side relief recess, the discharge-side relief recess, the relief flow passage, and a spool that closes or opens the relief flow passage, wherein the protruding portion overlaps with the bosses in a thickness direction, the protruding portion is formed between fitting holes on the surface of the housing, characterized in that the protruding portion is in the form of a block and protrudes in a thickness direction (z), in the surface of the housing, the position of the protruding portion in the plane direction is different from the positions at which the fitting portions are formed, and the positions of the suction-side relief recess and the discharge-side relief recess in the plane direction correspond to a position at which the protruding portion is formed.