<p>A diaphragm pump with a flat diaphragm which is held between the face surface of a pump head and the corresponding face surface of a hydraulic block is improved in that the annular clamping region has an angling step such that the clamped-in diaphragm is bent in its outer annular border region. In this way, a sealed tightness is achieved over long time periods, as well as inducing a uniform diaphragm tension which effects performance of the pump advantageously. Inventive valve designs are provided which allow removal for cleaning from outside the assembled pump and also allows manual opening of the valves for unclogging. An efficient design is provided for a pump head.</p>