To suppress deterioration of heating efficiency during heating operation.

The heat storage type air conditioner is provided with a primary side circuit 3 guiding and circulating a first heating medium heated or cooled by a heat pump heat source machine 1 having a compressor 7, an air side heat exchanger 15, an expansion valve 13, and a primary side heat exchanger 11 to a heat storage tank 27 or a heat exchanger 25, a secondary side circuit 5 circulating a second heating medium between the heat storage tank 27, the heat exchanger 25, and an air conditioning load 29, and a control means for operating the heat pump heat source machine 1 and the primary side circuit 3 during a set time zone, and heating or cooling the second heating medium in the heat storage tank 27 to store heat. In the control means, a route of the first medium is changed to a heat exchanger 25 side during heating operation of the air conditioning load 29, the second heating medium heated to a first heating temperature by the heat exchanger 25 is guided to the heat storage tank 27, it is heated to a second heating temperature higher than the first heating temperature, and it is supplied to the air conditioning load 29.