There is provided a hybrid turbocharger that allows easy and quick attachment/removal of a coupling attachment boss to which an end section of a coupling is attached, thereby reducing the amount of operation time required for an overhaul of the turbocharger. The hybrid turbocharger includes: a turbine section that is driven by exhaust gas introduced from an internal combustion engine; a compressor section that is driven by the turbine section to pressure-feed outside air into the internal combustion engine; and a power generator having a rotating shaft coupled to a rotating shaft of the turbine section and the compressor section via a coupling. A coupling attachment boss to which one end section of the coupling is coupled, intervenes and is fixed, via a boss fixing nut that screws onto a screw section formed on a tip end of one end section of the rotating shaft of the turbine section and the compressor section, between one end surface of a turbine rotor that constitutes the turbine section or one end surface of a compressor impeller that constitutes the compressor section, and the boss fixing nut.