A milk pump for pumping milk from a womans breast, includes a receptacle for receiving milk pumped from the womans breast and a manual pumping unit. The pumping unit includes a displacement space surrounded by a wall that defines a longitudinal axis and having a predetermined cross-sectional dimension. This displacement space is or may be connected to a breast hood. The pump unit includes a suction member which is displaceable within displacement space substantially along its longitudinal axis. The suction member is formed as a generally cup-shaped membrane so that a first portion of said cup-shaped membrane extends transversely to the longitudinal axis of said displacement space, whereas a second portion extends substantially in circumferential direction. The membrane is able to move substantially free of friction relative to a wall of the displacement space.
