Assembly (1) adapted to contain a fluid, in particular a cosmetic fluid, including a bottle (2) extending in an elongate direction (6) and including a neck (30), a substantially tubular base (4) substantially covering the bottle and retaining part adapted to hold the bottle in the base. The retaining part including a collar (16) bearing on the bottle about its neck, a tubular member (8) and hooking part (18, 20). The tubular member (8) includes elastic part (10) disposed between a first portion (12) and a second portion (14) of the tubular member in order to be able to vary the distance between the first portion (12) and the second portion (14) of the tubular member, the tubular member (8) being connected to the base (4) by its second portion (14). The hooking part is adapted to secure the collar (16) to the first portion (12) of the tubular member.