The present invention relates to a method of producing aromatic amines by hydrogenation of aromatic nitro compounds. This method provides a reactor containing a hydrogenation catalyst; supplies aromatic nitro compounds and hydrogen to the reactor and contacts them with a hydrogenation catalyst, in which the hydrogen which is supplied to the reactor is by a compressor and the compressor contains an operating fluid which at least partially contacts the hydrogen; and regenerates the hydrogenation catalyst by heating and contacting it with oxygen. Particular operating liquids are subsequently exchanged.