The aim of the invention is to connect a nebulizer to a breathing air tube of a respirator. Said aim is achieved by a nebulizer-connecting device comprising a breathing air-directing unit (1) that is provided with a first mechanism (1a) for connecting a duct supplying breathing air, a second mechanism (1b) for connecting a duct evacuating breathing air, and a third mechanism (1c) for connecting the nebulizer, and a sealing unit (10) which is arranged on the third connecting mechanism (1c) and by means of which a flow path for an aerosol generated by the nebulizer can be unblocked when the nebulizer (5) is connected while said flow path for an aerosol generated by the nebulizer can be sealed therewith when the nebulizer (5) is removed. A sealing member (11) is opened when the nebulizer (5) is connected while being closed when the nebulizer (5) is removed.