Provided is an air conditioner for performing heating operation through supply of a current to a heating portion including a plurality of positive temperature coefficient (PTC) heaters to be connected to a power supply section, the air conditioner including: a heater output control section for controlling an output of the heating portion; and a plurality of pulse signal generating sections provided correspondingly to the plurality of PTC heaters, each for generating a predetermined pulse signal when a corresponding one of the plurality of PTC heaters is supplied with the current, in which the plurality of PTC heaters are subjected to detection as to whether each of the PTC heaters is in a connected state or in a non-connected state based on presence/absence of the predetermined pulse signal, and the heater output control section subjects the heating portion to output control which is adjusted according to the number of the PTC heaters in the connected state.