In the head 26 of a micropump 10, the intake pipe 28 protrudes internally, forming a projection 34 with inclined top base; the hole 30' of the discharge pipe 30 opens into a seat 36, lowered with respect to the bottom of the head 26, with inclined lower base, parallel to the top base of the projection 34. A gasket 42, with diametral sector 44 from which opposed lids 46, 46' , develop, is arranged in the head 26 and is compressed by a ring 38; these lids are oriented angularly in correspondence with the top base of the projection 34 and of the bottom base of the seat 36. A diaphragm 40 is activated by a piston 20 which makes it rise and fall, determining the consequent analogous movement of the above-mentioned lids which act as valves. At the same time, the gasket 42 constitutes the sealing component between the head 26 and top ring 38.