The present invention discloses a heat source device in which the stop of an inverter device can be known by a control device of the heat source device and whose stabilized operation time period can be extended. The heat source device is driven by the inverter device having a protective function for stopping, in order to protect devices, the inverter device based on predetermined calculation by an inverter control section. The heat source device has an electric compressor for compressing refrigerant and also has a control device for controlling a cold heat output and/or a hot heat output. Thecontrol device has an inverter protective function estimating section for estimating the result of calculation for the protective function by the inverter control section.