A control diaphragm for controlling fuel supply in a carburetor of an internal combustion engine includes a functional region enclosing a sensing region concentrically and a peripheral fastening border for fastening the control diaphragm in the diaphragm carburetor. The control diaphragm closes a control chamber of the diaphragm carburetor and is operatively connected via the central sensing region to a control lever in the control chamber and senses the axial deflection of the sensing region in a manner dependent on operation-induced pressure change in the control chamber. The control diaphragm consists in one piece of temperature-resistant and fuel-resistant, non-elastomeric plastic and the functional region is configured by way of a multiplicity of concentric corrugations. The outermost corrugation directly adjoins the fastening border, and the radius of the outermost corrugation corresponds substantially to the radius of the control chamber. The sensing region directly adjoins the innermost corrugation and the radius of the sensing region corresponds to from 5 to 25% of the outer radius of the functional region.