To prevent a dew generated at an inner wall of an aeration passage of an air conditioner from being produced.

In an air conditioner in which an air suction port and an air blowing port are connected by an aeration passage 5 and a heat exchanger 6 is provided across within the aeration passage 5, a band-like seal member 10 made of independent foamed material is provided along a clearance between an upper end of the heat exchanger 6 and a defining wall 5a defining and forming the aeration passage 5.