To provide a heat exchanger capable of further improving strength or rigidity of an air conditioner, particularly, rigidity to bending, twisting or the like acting on a top plate, a bottom plate or the like of a casing by being stored in the casing of the air conditioner or by being connected with another component, and an air conditioner containing it.

The heat exchanger C comprises a heat exchange unit C1 formed in a flat sheet form and heat exchange units C2 and C3 formed in a sheet form having a bent part bent in substantially L-shape in a plane vision, which are arranged in layers in a passing direction of air, and each holding part of each of the heat exchange units C1, C2 and C3 is integrated (connected) between different heat exchange units.