Abstract: A diaphragm dosing pump (1) has a rotary driving motor (3) electrically connected to control electronics (4). The motor is controlled in such a way that at the beginning and end of each dosing operation the driven diaphragm preferably always takes the same starting position, in particular a bottom dead center position. In order to achieve a reliable sealing behavior of the inlet and outlet valves even during slow working strokes and when the pressure difference between suction and compression sides is small, the valves are designed with elastic valve disks mounted without stress between their valve seat and an opposite rib-like stop.