A multi-stage supercharging device in modular form which, as exhaust-side assembly, comprises at least one high-pressure turbine having a high-pressure turbine rotor and a high-pressure turbine housing, a low-pressure turbine with a low-pressure turbine rotor and a low-pressure turbine housing and an exhaust gas outflow housing, and which, as charge air-side assembly, comprises at least one high-pressure compressor with a high-pressure compressor rotor and a high-pressure compressor housing, a low-pressure compressor with a low-pressure compressor rotor and a low-pressure compressor housing and a charge air cooler connected between the low-pressure compressor and the high-pressure compressor, wherein the supercharging device can be assembled from multiple modules of a modular system, namely in such a manner that: the charge air-side modules, namely at least the high-pressure compressor with the high-pressure compressor rotor and the high-pressure compressor housing, the low-pressure compressor with the low-pressure compressor rotor and the low-pressure compressor housing and the charge air cooler connected between the low-pressure compressor and the high-pressure compressor are independent of whether the high-pressure turbine is embodied as a radial turbine or as an axial turbine and whether the low-pressure turbine is embodied as a radial turbine or as an axial turbine, and of whether the supercharging device is designed without exhaust gas after-treatment or with exhaust gas after-treatment between the high-pressure turbine and the low-pressure turbine; as exhaust-side modules, the high-pressure turbine with the high-pressure turbine rotor and the high-pressure turbine housing and the low-pressure turbine with the low-pressure turbine rotor and the low-pressure turbine housing are dependent on whether the high-pressure turbine is embodied as a radial turbine or as an axial turbine and whether the low-pressure turbine is embodied as a radial turbine or as an axial turbine; as exhaust-side modules, the high-pressure turbine housing and the low-pressure turbine housing are dependent on whether the supercharging device is designed without exhaust gas after-treatment or with exhaust gas after-treatment between the high-pressure turbine and the low-pressure turbine. the charge air-side modules, namely at least the high-pressure compressor with the high-pressure compressor rotor and the high-pressure compressor housing, the low-pressure compressor with the low-pressure compressor rotor and the low-pressure compressor housing and the charge air cooler connected between the low-pressure compressor and the high-pressure compressor are independent of whether the high-pressure turbine is embodied as a radial turbine or as an axial turbine and whether the low-pressure turbine is embodied as a radial turbine or as an axial turbine, and of whether the supercharging device is designed without exhaust gas after-treatment or with exhaust gas after-treatment between the high-pressure turbine and the low-pressure turbine; as exhaust-side modules, the high-pressure turbine with the high-pressure turbine rotor and the high-pressure turbine housing and the low-pressure turbine with the low-pressure turbine rotor and the low-pressure turbine housing are dependent on whether the high-pressure turbine is embodied as a radial turbine or as an axial turbine and whether the low-pressure turbine is embodied as a radial turbine or as an axial turbine; as exhaust-side modules, the high-pressure turbine housing and the low-pressure turbine housing are dependent on whether the supercharging device is designed without exhaust gas after-treatment or with exhaust gas after-treatment between the high-pressure turbine and the low-pressure turbine.