The invention relates to a pump for dispensing a fluid material, comprising a first piston (10), a second piston (20), and a dispensing head (40) provided with a dispensing opening (45) for actuating said pump, a stopper (50) being arranged upstream from said dispensing opening (45), said stopper (50) being movable between a position for closing said dispensing opening (45) and a position for opening the latter, said second piston (20) being formed outside a hollow part (25) sliding into said dispensing head (40), said first piston (10) sliding inside said hollow part (25), said hollow part (25) comprising an axial opening defined by a radial edge (26) through which a rod portion (52) of the stopper (50) passes, said rod portion (52) being defined between a proximal radial shoulder (56) and a distal radial shoulder (57) of the stopper (50). Said stopper (50) is moved from the closed position thereof to the open position thereof by means of said radial edge (26) of said hollow part (25), which engages with said distal radial shoulder (57), and is moved from the open position thereof to the closed position thereof by means of said radial edge (26), which engages with said proximal radial shoulder (56).Pompe de distribution de produit fluide comportant un premier piston (10), un second piston (20) et une tête de distribution (40) pourvue dun orifice de distribution (45) pour actionner ladite pompe, un obturateur (50) étant disposé en amont dudit orifice de distribution (45), ledit obturateur (50) étant déplaçable entre des positions dobturation et douverture dudit orifice de distribution (45), ledit second piston (20) étant formé à lextérieur dune pièce creuse (25) coulissant dans ladite tête de distribution (40), ledit premier piston (10) coulissant à lintérieur de ladite pièce creuse (25), ladite pièce creuse (25) comportant une ouverture axiale définie par un bord radial (26) à travers laquelle passe une partie de tige (52) de lobturateur (50), ladite partie de tige
