To provide an air conditioner equipped with a pressure release means being constituted simply capably of setting the action pressure for pressure release low.

This air conditioner is equipped with a heat accumulating container 14 in which heat accumulating material 16 is accommodated and a part of the refrigerant circulating in the freezing cycle passes and which is sealed to heat the passed refrigerant, a heating means 17 for heating the heat accumulating material within the heat accumulating container, and a pressure release means 18 for releasing the pressure when the pressure within the heat accumulating container comes to a specified pressure or over, and the pressure release means 18 has a fixing part 32 in which a connection hole leading to the interior of the heat accumulating container 14 and which is fixed to the outer wall of the heat accumulating container 14, and a pressure receiving plate 34 which is fixed to the fixing part 32 at plural points as to block the connection hole and can form a space between itself and the fixing part 32 so as to release the pressure when the pressure within the heat accumulating container 14 comes to the specified pressure or over.