Abstract: An indoor unit of an air conditioner with an electronic expansion valve. The indoor unit includes a main body, a heat exchanger disposed at the front portion of the inside of the main body, a control unit, in which electrical components are mounted, disposed at the outside in the lengthwise direction of the heat exchanger, a control case including a first side surface part disposed between the control unit and the heat exchanger and an extension part connected with the first side surface part and extended in the lengthwise direction of the heat exchanger, and an electronic expansion valve disposed in a space defined by two surfaces neighboring with each other by the extension part.