To provide an indoor unit for an air conditioner capable of preventing the drip of drain water from a heat exchanger to a blower fan in a configuration of disposing the heat exchanger of a circular shape concentric with the blower fan in an upper part of the blower fan.

The heat exchanger 2 having a plurality of circular heat exchanger plates 21 formed in circular shapes concentric with a cross flow fan 3, and a plurality of pieces of refrigerant piping 22 inserted through the plurality of heat exchanger plates 21 has non-heat exchange parts R1 not pierced by the refrigerant piping 22 in each top of the circular heat exchanger plates 21 positioned in a vertical upward direction of a rotation axis of the cross flow fan 3. A wind-breaking plate 5 (blast limiting member) limiting the passage of blast through the non-heat exchange part R1 is provided at either or both of an upstream side and a downstream side of a blast direction by the cross flow fan 3 of the non-heat exchange part R1 of the heat exchanger 2. By this, the generation of drain water in the non-heat exchange parts R1 can be suppressed.