A power generating apparatus of renewable energy type includes a tower, a nacelle which is supported rotatably by a tip portion of the tower; a main shaft rotatable with a blade; a hydraulic pump which is housed in the nacelle and is driven by rotation of the main shaft; a hydraulic motor which is driven by operating oil supplied from the hydraulic pump; a generator which is coupled to the hydraulic motor; an operating-oil line which is provided between the hydraulic pump and the hydraulic motor and through which the operating oil circulates; a cooling-medium line through which cooling medium for cooling the operating oil circulates via an intermediate heat exchanger; and a main heat exchanger which cools the cooling medium by heat exchange with cool water source around a base portion of the tower, and one of the operating-oil line.