Indoor unit of air conditioner

The utility model provides an indoor unit of an air conditioner. Relates to the technical field of air conditioning. The air conditioner indoor unit comprises a machine shell, the machine shell extends in the horizontal direction, and an air supply opening and an air return opening are formed in the front surface of the machine shell and are sequentially formed in the length direction of the machine shell. According to the air conditioner indoor unit, the air inlet and the air return opening are formed in the front surface of the machine shell, and therefore air can enter the air conditioner indoor unit from the front and can be supplied from the front. In this way, the installation position of the air conditioner indoor unit is not affected by air supply and air return, the air conditioner indoor unit can be completely embedded into a room, namely the lower surface and the rear surface of the air conditioner indoor unit can be completely attached to the indoor ground and the indoor wall, and the installation