PROBLEM TO BE SOLVED: To provide a heat pump hot water heating apparatus capable of maximizing an operation efficiency by continuing the control of a circulation pump while the operation efficiency of an apparatus changes from an increase to a decrease, and by determining a heat medium circulation amount in which the operation efficiency becomes maximum.SOLUTION: The heat pump hot water heating apparatus includes: a heat pump cycle 110 in which a compressor 111 for compressing a cooling medium, a cooling medium-heat medium heat exchanger 115, depressurizing means 114 and an evaporator 112 are connected in an annular shape, and in which the cooling medium circulates; and a heat medium cycle in which a circulation pump 121, a radiator 125, the cooling medium-heat medium heat exchanger 115 are connected in an annular shape, and in which a heat medium for exchanging heat with the cooling medium at the cooling medium-heat medium heat exchanger 115 circulates. A control device 130 performs adjustment so that the op
