A cartridge containing aromatic constituents is inserted to an efficacious constituent supply apparatus which is embedded in a door. An insertion slot of the cartridge is formed on a matching surface of the door trim, the surface facing an side surface of an instrument panel. BY forming the insertion slot on the matching surface of the door trim, the insertion slot can be concealed when the door is closed and thus the appearance of the efficacious constituent supply apparatus can be enhanced. In addition, the insertion slot is exposed when the door is opened, working efficiency upon changing the cartridge is not impaired.
