The invention relates to a fluid product dispensing member that comprises a dispensing wall (23) defining an outer surface (231) and an inner surface (232). The wall (23) is provided with a dispensing opening (24) formed therethrough that connects the inner surface and the outer surface. The inner surface (232) defines a sealed sliding sheath (233) for a piston (3) capable of moving along an axis and in sealed contact with the sheath from a rest position for opening an outlet valve (25, 35). The piston (3) defines a portion of a fluid product chamber (20) in which the fluid product is selectively pressurized and discharged through the open outlet valve towards the dispensing opening. The invention is characterized in that the piston defines a stopper wall (34) capable of blocking the dispensing opening (24) in the rest position. The inner surface (232) is inclined within the dispensing opening (24) relative to the movement axis X of the piston (3). The stopper wall (34) of the piston (3) is inclined in a manner substantially corresponding to the inner surface (232) so as to generate a taper-to-taper contact.