A diaphragm valve includes a diaphragm with a rigid insert. The diaphragm is arranged over a valve seat. The diaphragm is clamped concentrically around said valve seat. The combination of the rigid insert and the clamp enable a pressure applied an area of said diaphragm outside said clamped area to be communicated to the area of the diaphragm inside said clamped area, thereby closing or opening said valve seat. The invention is directed to a diaphragm valve in which at least one circular valve seat is arranged within the housing and which can be actuated by a diaphragm-like actuating element so as to open from the valve seat or close on the valve seat. Valves of this kind are known as diaphragm valves because the actual valve element is a flexible diaphragm. Strictly speaking, these valves are known as diaphragm seat valves. In view of the fact that the valve element is a diaphragm, such valves are naturally constructed in a flat manner. Often, a plurality of such valve seats and consequently also a plurality of diaphragms is accommodated within such valves. These can be discrete component parts which are actuated individually and which are accordingly separate or they can be integrated in one piece, depending on the desired directional valve function. To achieve a corresponding valve function, two valves are usually necessary, on which valves two diaphragms or two diaphragm portions can be actuated. Because the diameter of the valve seats is necessarily large, the resulting valve has correspondingly wide dimensions.