An indoor unit for an air conditioner provided in a ceiling, the indoor unit comprising: an indoor unit body including an indoor fan and an indoor heat exchanger inside, mounted in the ceiling, controlling a temperature of air sucked from below, and blowing out the air; and a decorative panel provided under the indoor unit body, wherein the decorative panel includes a panel body vertically penetrated by an air inlet at its central portion, and by air outlets around the air inlet, a plate member, and four suspending supports, each of which including a first extension and a second extension characterized in that: the first extension of each suspending support extends inward from a portion of the panel body forming the air inlet, each first extension extending inward from an inner peripheral portion of the air inlet, the plate member being connected to a lower portion of the first extension of each of the four suspending supports, the respective second extension is integral with the first extension, and extends downward from a tip portion of the first extension, and that the indoor unit further comprises: a grille being a square or rectangular plate smaller than the air inlet, which has a square or rectangular shape in plan view, and connected to a lower end of the second extension of each of the suspending supports, provided at a lower end portion of the air inlet, and covering a central portion of the air inlet to form an inlet opening between an outer peripheral edge of the grille and an opening edge of the air inlet in plan view. an indoor unit body including an indoor fan and an indoor heat exchanger inside, mounted in the ceiling, controlling a temperature of air sucked from below, and blowing out the air; and a decorative panel provided under the indoor unit body, wherein the decorative panel includes a panel body vertically penetrated by an air inlet at its central portion, and by air outlets around the air inlet, a plate member, and four suspending supports, each of which including a first extension and a second extension a panel body vertically penetrated by an air inlet at its central portion, and by air outlets around the air inlet, a plate member, and four suspending supports, each of which including a first extension and a second extension characterized in that: the first extension of each suspending support extends inward from a portion of the panel body forming the air inlet, each first extension extending inward from an inner peripheral portion of the air inlet, the plate member being connected to a lower portion of the first extension of each of the four suspending supports, the respective second extension is integral with the first extension, and extends downward from a tip portion of the first extension, and that the indoor unit further comprises: a grille being a square or rectangular plate smaller than the air inlet, which has a square or rectangular shape in plan view, and connected to a lower end of the second extension of each of the suspending supports, provided at a lower end portion of the air inlet, and covering a central portion of the air inlet to form an inlet opening between an outer peripheral edge of the grille and an opening edge of the air inlet in plan view. the first extension of each suspending support extends inward from a portion of the panel body forming the air inlet, each first extension extending inward from an inner peripheral portion of the air inlet, the plate member being connected to a lower portion of the first extension of each of the four suspending supports, the respective second extension is integral with the first extension, and extends downward from a tip portion of the first extension, and that the indoor unit further comprises: a grille being a square or rectangular plate smaller than the air inlet, which has a square or rectangular shape in plan view, and connected to a lower end of the second extension of each of the suspending supports, provided at a lower end portion of the air inlet, and covering a central portion of the air inlet to form an inlet opening between an outer peripheral edge of the grille and an opening edge of the air inlet in plan view.