To provide an indoor unit of an air conditioner capable of correctly detecting a floor surface temperature while avoiding obstacles such as a table and a sofa.

This indoor unit 1 of the air conditioner houses a heat exchanger 15 and a cross flow fan 16 in a housing 10, and a floor surface temperature sensor 21 detecting a surface temperature of a floor F of an air-conditioned space is disposed at a front side of the housing 10. A control section of the indoor unit 1 controls an operation on the basis of a result of the detection by the floor surface temperature sensor 21. A detection range 22 of the floor surface temperature sensor 21 has directionality, and the indoor unit 1 loads the floor surface temperature sensor 21 in a state that its detecting direction is variable by an universal mount 24. The universal mount 23 is provided with a knob 25 for changing the detecting direction of the floor surface temperature sensor 21. The knob 25 takes a horizontal attitude when the floor surface temperature sensor 21 faces the direction determined as the standard.