PURPOSE: To make the maintenance of the device simple and to positively hold the filter function by loading in a freely attachable and detachable manner a grill plate in which an indoor suction port of a blasting circuit is widely opened and a filter is fixedly provided on the back surface in a home air conditioner.

CONSTITUTION: An indoor unit of an indoor and outdoor separate type air conditioner is provided in the front of a front surface grill 1 with opening 1b each having a hooked part 1c at the upper and lower part, and a grill plate 4 provided on its back surface with a filter 4 in a freely attachable and detachable manner. Accordingly, cleaning of the filter 4 can be carried out by removing the filter 4 from the front surface grill 1 together with the grill plate 5. Therefore, cleaning of the filter 4 can be conducted not only easily but also completely. Thus, the structure of the front grill becomes compact, and upon cleaning of the filter, dirts stacked on the filter can be prevented from dropping into the air conditioner, and hence, the device is excellent from the sanitary point of view and can surely maintain the filter function.