The invention relates to an evaporation device for evaporating volatile substances, comprising a container (1) housing a liquid (8) containing the volatile substances, an outlet (2) through which the volatile substances exit and a hole (9) for equalizing the pressure between the inside and the outside of the container, and characterized in that it also comprises a membrane (6) placed between the container (1) and the hole (9), said membrane (6) being leak-tight with respect to said liquid (8) and porous with respect to the gases.
This membrane prevents the liquid from accidentally spilling and furthermore solves the issue of balancing pressures inside the container, keeping the rate of evaporation constant until running out of the volatile substances.