The present invention provides an indoor unit for air conditioner which can improve construction quality and can regulate the air for the space with high hot load without damaging the appearance and its arrangement structure. The indoor unit (1) for air conditioner is provided with a body box part (2) which has a bottom opening and is mounted with a blower (6) and a heat exchanger (7), and a windpassage frame (4) composed of a plate frame (3) which is rectangle observed from the bottom and covers the bottom opening of the body box part; the internal part of the wind passage frame is divided into a suction side wind passage (14) and a blow side wind passage (5) by the heat exchanger (7), a suction port (16) for indoor air is formed at the position connecting the suction side wind passage (14) and the plate frame (3), two direction blow ports of a fist blow port (17) and a second blow port (18) are disposed at the position connecting the blow side wind passage (15) and the plate frame (3) along two opposite sides of the plate frame (3); a third blow port (19) connecting the blow side wind passage (15) is disposed on the plate frame (3) along one side of the two opposite sides.