A compressed air energy storage power generation apparatus includes a power demand receiving unit that receives a power demand value of a consumer facility. The apparatus includes a first air supply valve that adjusts a flow rate of compressed air to be supplied from a low-pressure tank to an expander, a second air supply valve that adjusts a flow rate of compressed air to be supplied from a high-pressure tank to the expander, and a control device configured to open the first air supply valve according to the power demand value in a state where the second air supply valve is closed when the power demand value is less than a predetermined threshold, and to open the second air supply valve according to the power demand value when the power demand value is equal to or greater than the predetermined threshold.