A diaphragm pump is provided. The diaphragm pump comprises an upper and lower housing, a pump chamber plate, a pair of pump chambers, and a diaphragm that separates the pair of pump chambers. First and second suction-side check valves are disposed between the pair of pump chambers and a suction port. First and second discharge-side check valves are disposed between the pair of pump chambers and a discharge port. The lower housing comprises a first pump chamber concave portion. The pump chamber plate comprises a second pump chamber concave portion, the second suction-side check valve, and the second discharge-side check valve. An interplate suction-side channel and an interplate discharge-side channel are provided between the upper housing and the pump chamber plate.