Abstract: A dispenser having a reservoir module (R?) havingn a case (RT) for accommodating a fluid product cartridge (C) defining a movable wall (C2) biased by a spring (R4) resting on a bearing (R31); and a dispensing module having an outlet valve for controlling the passage of the fluid product released under pressure from the fluid product cartridge (C). The reservoir module (R?) is removably connected to the dispensing module. The bearing (R31) of the spring (R4) is movable relative to the casing (R1?) between an active position in which the spring (R4) is compressed and a rest position in which the spring (R4) is relaxed, thereby allowing the reservoir module (R?) to be connected to the dispensing module with the bearing (R31) in the rest position and the bearing (R31) subsequently in the active position.