PURPOSE: To shorten the rising time of the heating temperature at the time of heating operation of the heat pump type air conditioner by a method wherein not only the room temperature but also the wall temperature are constantly detected and even when the room temperature exceeds a target room temperature value, the heating operation is continued to thereby heat the inner wall of the room.

CONSTITUTION: An auxiliary adjuster 15 gives to a main adjuster 14a value higher than the target room temperature value θ1 as a newly set temperature value θ2 for a period from the initiation of the heating operation up to a time T3 because the difference between the wall temperature and the target value θ1 is higher than a preset value (Δθ). Therefore, even when the room temperature reaches the original target value θ1, the air conditioner continues its heating operation so that heat meeting the heat capacity of the inner wall of the room is radiated into the room to thereby guarantee the heat radiation from the wall. Next, when the time T3 is reached, the inner wall of the room is heated sufficently so that the difference between the wall temperature and the target room temperature θ1 becomes equal to the set value Δθ. Accordingly, the auxiliary adjuster 15a varies the set value θ2to give the main adjuster 14a the target value θ1 and as a matter of course, the room temperature becomes higher than the target value θ1 to thereby stop the heating operation of the air conditioner.