A diaphragm pump with a pump lid, a pump housing and a hydraulically powered diaphragm that is arranged between the former, that delimits a hydraulic chamber from a delivery chamber and that is clamped in a circulating rim. There is provided between the pump lid and the pump housing an insert part, which is located on the side of the pump lid and which limits the delivery chamber and/or an insert part that is located on the side of the pump housing and that delimits the hydraulic chamber, while the diaphragm at its circulating rim is clamped between the insert part and the pump housing or the pump lid or between insert parts.