PURPOSE: To provide an automotive air conditioner constituted in such a way as to perform dehumidifying heating in addition to cooling and heating by using one evaporator.

CONSTITUTION: Refrigerant from a compressor 11 is made branch off to a first passage 13 or a second passage 14 by a three-way valve 12. The output refrigerant from a condenser 15 set to the first passage 13 is circulated in series to two chambers 211, 212, forming an evaporator 21, through an expansion valve 20 to set a cooling mode. The refrigerant is made flow from the second passage 14 making a detour around the condenser 15 and expansion valve 20 to perform heating operation. It is so constituted that an expansion valve 25 is interposed between the first chamber 211 and second chamber 212 of the evaporator 21 in the state of heating operation, so that the first chamber 211 is made into a condenser, and the second chamber 212 is made into an evaporator to perform dehumidifying heating operation.