A compressed air energy storage power generation device equipped with: a compressor mechanically connected to a motor; a first pressure storage tank storing compressed air from the compressor; an expansion device driven by compressed air from the tank; a generator mechanically connected to the expansion device; a first heat exchanger that exchanges heat between a heat medium and the compressed air supplied from the compressor to the tank; a second heat exchanger that exchanges heat between the heat medium and the compressed air supplied from the tank to the expansion device; a pressure sensor that detects the state of charge (SOC) of the tank; SOC adjustment units that adjusts the SOC; and a control device. The control device controls the SOC adjustment units such that the detected SOC is within an optimal SOC range while satisfying the requested power. Thus, in this compressed air energy storage power generation device the SOC is controlled so as to be within an optimal SOC range, so the operating efficiency can be improved.