The invention relates to a dispenser for a substance, comprising a housing (1), a reservoir (2), a metering valve (3), and an actuator (4). In known dispensers, the metering valve (3) is positively coupled to the actuator (4) via coupling means when the metering valve is activated for the first time. The invention is characterized in that the coupling means can be activated by inserting a the reservoir (2) into the housing (1) and by the respective relative movement between the housing (1) and the reservoir (2) in the direction of insertion (E) thereby eliminating an idle movement after the insertion of the reservoir.