To sustain decorative design without sacrifice of appearance by providing an air filter having a predetermined decorative design at a position corresponding to a part of a front opening where a shield panel having a gap in the back and forth direction is not lapped over a panel body in front view thereby ensuring the suction area of a front panel.

A shield panel 23 substantially overlapping a front opening 28 in front view is provided in front of the front opening 28. The shield panel 23 is jointed to a front panel body 22 at the lower part and spaced apart forward from the front opening 28 by a specified distance. A gap is provided in back and forth direction between the front panel body 22 and the shield panel 23 from the vicinity of upper edge to the side edge of the front opening 28 and that gas constitutes a front suction opening 29 for sucking indoor air from the front. Frame part of an air filter 21 is constituted at a position corresponding to the vicinity of the front suction opening 29 and a predetermined decorative design is applied to that part.