Abstract: The present invention provides an indoor unit of an air conditioner, which is capable of improving the safety regarding the opening and closing movements of a movable panel. An indoor unit of an air conditioner includes a front grill, a second panel, a driving machine, and a second panel supporting member. The front grill is provided with a first intake port at a front thereof. The second panel is provided such that it covers the first intake port, opens the first intake port by moving away from the first intake port and closes the first intake port by moving close to the first intake port. The driving machine generates a driving force to move the second panel. The second panel supporting member has a gear portion and a plate member. The gear portion transmits the driving force of the driving machine to the second panel. The plate member is provided outside the gear portion, and covers a gap between the second panel and the front grill in a state in which the second panel is open.