A gas turbine comprising: a compressor rotor having a plurality of compressor rotor disks; a turbine rotor having a plurality of turbine rotor disks; a connection part connecting the compressor rotor and the turbine rotor to each other; a tie rod extended centrally through the plurality of compressor rotor disks and central axes of the plurality of turbine rotor disks; and a clamping member forced onto the tie rod so as to be rotated with the tie rod, and relatively rotated with respect to an inner circumferential surface of the connection part, wherein the clamping member comprises: an inner ring pressed against an outer circumferential surface of the tie rod; a plurality of support parts arranged at predetermined intervals such that one ends thereof are connected to an outer circumferential surface of the inner ring and the other ends thereof are extended radially outside and along a circumferential direction of the inner ring, wherein the inner ring has a plurality of grooves formed in the circumferential direction thereof, such that the support parts are inserted into the respective grooves; and a plurality of stiffeners connected to the other ends of the support parts, respectively, and arranged along the circumferential direction of the inner ring while forming a concentric circle around a centre of the inner ring. a compressor rotor having a plurality of compressor rotor disks; a turbine rotor having a plurality of turbine rotor disks; a connection part connecting the compressor rotor and the turbine rotor to each other; a tie rod extended centrally through the plurality of compressor rotor disks and central axes of the plurality of turbine rotor disks; and a clamping member forced onto the tie rod so as to be rotated with the tie rod, and relatively rotated with respect to an inner circumferential surface of the connection part, wherein the clamping member comprises: an inner ring pressed against an outer circumferential surface of the tie rod; a plurality of support parts arranged at predetermined intervals such that one ends thereof are connected to an outer circumferential surface of the inner ring and the other ends thereof are extended radially outside and along a circumferential direction of the inner ring, wherein the inner ring has a plurality of grooves formed in the circumferential direction thereof, such that the support parts are inserted into the respective grooves; and a plurality of stiffeners connected to the other ends of the support parts, respectively, and arranged along the circumferential direction of the inner ring while forming a concentric circle around a centre of the inner ring. an inner ring pressed against an outer circumferential surface of the tie rod; a plurality of support parts arranged at predetermined intervals such that one ends thereof are connected to an outer circumferential surface of the inner ring and the other ends thereof are extended radially outside and along a circumferential direction of the inner ring, wherein the inner ring has a plurality of grooves formed in the circumferential direction thereof, such that the support parts are inserted into the respective grooves; and a plurality of stiffeners connected to the other ends of the support parts, respectively, and arranged along the circumferential direction of the inner ring while forming a concentric circle around a centre of the inner ring.