Provided is a heat source unit by which a time required for filling a cooling medium is shortened at the time of installing an air conditioning apparatus unit to be used. A heat source unit (1) is provided with: a compressor (100); a heat-source-side heat exchanger (200); a cooling medium regulator (61) having a cooling medium stored therein; introducing piping (62), which is branched from the jetting-side piping (110) of the compressor (100), is connected to the cooling medium regulator (61) and introduces the cooling medium jetted from the compressor (100) into the cooling medium regulator (61); and lead-out piping (63) which is connected to the suction-side piping (120) of the compressor (100) from the cooling medium regulator (61) and leads out the cooling medium stored in the cooling medium regulator (61) to the suction-side piping (120).
