A membrane suction pump unit has a dimensionally stable membrane frame (1), a dimensionally stable monobloc membrane cover (3), which has a pump chamber (31) with a floor region and a side wall (36) encircling the floor region and widening outwards away from the floor region, and a monobloc pump membrane (2), which has a membrane plate (20), a flexible membrane piston (21), at least one inlet valve flap (23) and at least one outlet valve flap (24). The membrane plate (20) is arranged between the membrane frame (1) and the membrane cover (3), and membrane frame (1), pump membrane (2) and membrane cover (3) are connected to one another by means of connecting elements (15, 15&prime；, 15&Prime；) in a preset position. The membrane piston (21) passes through the membrane frame (1), and the membrane piston (21) covers a pump chamber (31) of the membrane cover (3). According to the invention, there are more than three connecting elements (15, 15&prime；, 15&Prime；), forming a material and/or positive fit.
