Abstract: Valve intended to be used in particular in inhalation devices having a body, such as a spacer, the valve having a housing comprising an first part which is adapted to be mounted on an outlet opening of the body of the inhalation device, a second part on to which a mouthpiece or a face mask can be mounted, said first and second parts being provided with a first bore defining an inhalation channel, a first membrane provided in the inhalation channel and a second membrane, wherein the second part is provided with a second bore, said second bore defining the exhalation channel, the two channels being provided separated from one another and placed adjacent each other.