The compressor apparatus comprises a radial compressor (35) for the compression of a gas and also an electric motor (31) for driving the radial compressor (35), wherein the radial compressor (35) and the electric motor (31) are arranged in a pressure housing (1) which is provided with a gas inlet duct (2) and also a gas outlet duct (3), and also comprises an encapsulated apparatus (4) arranged in the pressure housing (1), the inner space of the encapsulated apparatus being fluid conductingly connected to a pressure reducing apparatus (37).