The present invention relates to a device (1) for automatic injection comprising a container (2), a piston (8) and:- a piston rod (9) coupled to said piston (8) during the injection,- biasing means (18) for causing distal movement of said piston rod (9) with respect to said container (2),- a housing (14； 214) receiving said container (2), said piston rod (9) and said biasing means (18),- controlling means (13, 22) for producing an audible indicator at the end of injection,characterized in that:said controlling means comprise one first element (13), flexible or breakable and coupled to said housing (14), or to said piston rod (9), during the injection, and one second element (22), coupled to said piston rod (9), or to said housing (14), during the injection, said first and second elements cooperating with each other at the end of injection under the effect of the said biasing means (18) to produce said audible indicator.
