A gas turbo set comprises a compressor, combustion chamber and turbine, a common rotor shaft having arranged on it, within the compressor, a plurality of rows of compressor moving blades and, within the turbine, a plurality of rows of turbine moving blades, which alternate with guide vane rows of compressor guide vanes and turbine guide vanes fastened to a carrying structure surrounding the rotor shaft on the outside. Simplified mounting/demounting is achieved with the compressor guide vanes and/or the turbine guide vanes of a guide vane row held in each case in a plurality of separate annular segments together forming a complete ring with at least one guide vane row, and with the annular segments fastened releasably to the carrying structure such that the annular segments, together with the compressor or turbine guide vanes fastened to them, can be removed individually from the carrying structure, while maintaining the carrying structure.