The invention relates to a micropump (10; 100) comprising at least a first plate (12), a second plate (20), an intermediate plate (18), a pump chamber (24), and inlet and outlet control members (28, 30). According to the invention, said inlet control member (28) is a non-return valve situated in the major portion of the thickness of said intermediate plate (18), being made of a moving member (40) and a membrane-forming portion (42) situated close to one of the plates (12, 20), connecting said moving member (40) to the remainder of said intermediate plate (18) and, by its resilience, enabling said valve (28) to move between a closed position and an open position, said moving member (40) having an orifice of limited volume passing therethrough.