In order to improve a turbo compressor comprising a compressor housing, in which an incoming gas volume flow is supplied to an impeller channel through an inlet channel, is compressed in the impeller channel by an impeller and is discharged from the impeller channel via an outlet channel, and a flow diversion channel which is provided in the compressor housing, extends outside of the impeller channel and the inlet channel, opens into the inlet channel with an opening on the inlet side and into the impeller channel with an opening on the impeller side and conveys a diversion volume flow between the openings as a function of a difference in pressure, in such a manner that it can be operated optimally with volume flows which are far below the volume flow provided for the design point it is suggested that the flow diversion channel have a cross-sectional flow area increasing in size up to the opening on the inlet side proceeding from the opening on the impeller side.