Abstract: The device comprises a pump (10) for delivering a liquid with a foaming agent from a container (R). The displacement of a rigid push-button (14) causes a variation in the volume of an annular chamber (13), and a return air inlet valve (22) allows for the inflow of air into this chamber. The end of the container (R) provided with the pump (10) is closed by a head (5) having a base (7) recessed with respect to the end of a central sleeve (8) carrying the pump and partly delimiting the said annular chamber (13), while the push-button (14) has in its base a collar (17) capable of closing the annular chamber (13) and compressing the air contained therein.