Abstract: There is provided an electromagnetically driven fluid pump. Even if deviation of a center plate from the diaphragm arises, centering of the center plate is carried out during the work for setting the center plate to an oscillator. The diaphragm and the center plate are fixed to the oscillator by means of a screw member, the diaphragm has a rising portion fitting to a through-hole at the center of the center plate, and the center plate has a ring-shaped rib on its surface where the screw member is inserted. The screw member is formed integrally with a washer portion and a diameter of the washer portion is nearly the same as an inner diameter of a bottom surface of the rib and the washer portion is formed so as to press a part of the rib in the case of maximum deviation of the center plate from the diaphragm.