Abstract: A diaphragm pump wherein the lower portion of an upright housing surrounds an eccentric extending into the annular lower end portion of the one-piece connecting rod the upper end portion of which extends through the central openings of two discs flanking the apertured central portion of a flexible diaphragm whose marginal portion is sealingly clamped between the main housing portion and a cover overlying the diaphragm. The top part of the upper end portion of the connecting rod is deformed to constitute a rivet head which sealingly fills the opening of at least one disc and urges the discs as well as the central portion of the diaphragm against the S-shaped surface of a carrier forming part of the connecting rod and serving to support the underside of the adjacent disc.