Abstract: A pulsation type diaphragm pump prevents back flow of a fuel and has reduced parts and assembly requirements. An intake valve disposed between an intake chamber and a pump chamber has an intake valve seat protruded to an inner portion of the pump chamber and an intake valve body formed by a portion of a pump diaphragm. The intake valve body opens and closes an intake valve seat port in cooperation with an intake seat surface in accordance with oscillation of the pump diaphragm. A discharge valve disposed between the pump chamber and a discharge chamber has a discharge valve seat protruded to an inner portion of the discharge chamber and a discharge valve body formed by a portion of a pulsator diaphragm. The discharge valve body opens and closes a discharge valve seat port in cooperation with a discharge seat surface in accordance with oscillation of the pulsator diaphragm.