A casing (10) of an indoor unit (1) contains an indoor fan (21), an air filter (30), and an indoor heat exchanger (22). The indoor unit (1) includes: a divider plate (25) which includes an air hole (26) for attaching the air filter (30) therein, and divides space inside the casing (10) into a room upstream of an air flow passing through the air filter (30), and a room downstream of the air flow passing through the air filter (30); a dust removing mechanism (50) for removing dust trapped on the air filter (30); and a dust container (90) for containing the dust which is removed by the dust removing mechanism (50), and is transferred through a transfer duct (88). The indoor heat exchanger (22) is arranged around the indoor fan (21), and the dust container (90) is arranged below the indoor heat exchanger (22).