Fluid substance dispensing device

A device (1) for dispensing a fluid substance, comprising a pressurized container (2) associated with a dispensing valve (4), the valve (4) having a supply conduit (9) and a stem (8) having a cavity (8A) through which the fluid substance is dispensed, a chamber (7), housed inside the container (2), and arranged so as to surround at least a part of a body (4A) of the valve (4), the chamber (7) being delimited by a deformable wall (6) and at least one part of the body (4A), the valve (4) being of the three-way type, configured so that when the stem (8) is in a first position, its cavity (8A) is isolated from the supply conduit (9) and from the chamber (7) while the supply conduit (9) is in communication with the chamber (7), wherein, when the stem (8) is in a second position, the cavity (8A) is in communication only with the chamber (7), and wherein, when the stem is in a third position, the cavity (8A) of the stem is in communication at least with the supply conduit (9), at least a part of the deformable wall (6) facing the inside of the pressurized container (2) so that when the stem (8) is in the second position the pressure inside the container (2) presses against the deformable wall (6), expelling the fluid substance contained inside the chamber (7).