A gas turbine comprising: an n-th stage stator blade having a plurality of stator-blade segments extending in a radial direction and provided at a predetermined pitch in a circumferential direction, n being a positive integer; an n-th stage rotor blade (5;1) disposed at a downstream side of the n-th stage stator blade in a direction of flow of combustion gas, the n-th stage rotor blade (5;1) having a plurality of rotor-blade segments (15;11) extending in the radial direction and provided around an outer periphery of a rotor at a predetermined pitch in the circumferential direction; an (n+1)-th stage stator blade (7;3) disposed at the downstream side of the n-th stage rotor blade (5;1) in the direction of flow of the combustion gas, the (n+1)-th stage stator blade (7;3) having a plurality of stator-blade segments (17;13) extending in the radial direction and provided at a predetermined pitch in the circumferential direction; an (n+1)-th stage rotor blade disposed at the downstream side of the (n+1)-th stage stator blade (7;3) in the direction of flow of the combustion gas, the (n+1)-th stage rotor blade having a plurality of rotor-blade segments extending in the radial direction and provided around the outer periphery of the rotor at a predetermined pitch in the circumferential direction; and a cavity formed between the n-th stage rotor blade (5;1) and the (n+1)-th stage stator blade (7;3), wherein the cavity is arranged such that it can be supplied with sealing air which leaks into the flow of combustion gas, wherein a blade-count difference between the stator-blade segments of the n-th stage stator blade and the stator-blade segments (17;13) of the (n+1)-th stage stator blade (7;3) is set to zero or to five or more, and/or a blade-count difference between the rotor-blade segments (15;11) of the n-th stage rotor blade (5;1) and the rotor-blade segments of the (n+1)-th stage rotor blade is set to zero or to five or more, and wherein a relative position between the n-th stage stator blade and the (n+1)-th stage stator blade (7;3) in the circumferential direction is set such that a wake flow produced by the stator-blade segments of the n-th stage stator blade is guided to a ±1/4 pitch region in the circumferential direction with respect to a leading edge of each stator-blade segment (17;13) of the (n+1)-th stage stator blade (7;3) and within a range of 0% to 15% and/or a range of 85% to 100% of the length in a span direction from a hub side of the stator-blade segment (17;13) of the (n+1)-th stage stator blade (7;3), one pitch being equal to a distance between adjacent stator-blade segments (17;13) in the circumferential direction. an n-th stage stator blade having a plurality of stator-blade segments extending in a radial direction and provided at a predetermined pitch in a circumferential direction, n being a positive integer; an n-th stage rotor blade (5;1) disposed at a downstream side of the n-th stage stator blade in a direction of flow of combustion gas, the n-th stage rotor blade (5;1) having a plurality of rotor-blade segments (15;11) extending in the radial direction and provided around an outer periphery of a rotor at a predetermined pitch in the circumferential direction; an (n+1)-th stage stator blade (7;3) disposed at the downstream side of the n-th stage rotor blade (5;1) in the direction of flow of the combustion gas, the (n+1)-th stage stator blade (7;3) having a plurality of stator-blade segments (17;13) extending in the radial direction and provided at a predetermined pitch in the circumferential direction; an (n+1)-th stage rotor blade disposed at the downstream side of the (n+1)-th stage stator blade (7;3) in the direction of flow of the combustion gas, the (n+1)-th stage rotor blade having a plurality of rotor-blade segments extending in the radial direction and provided around the outer periphery of the rotor at a predetermined pitch in the circumferential direction; and a cavity formed between the n-th stage rotor blade (5;1) and the (n+1)-th stage stator blade (7;3), wherein the cavity is arranged such that it can be supplied with sealing air which leaks into the flow of combustion gas, wherein a blade-count difference between the stator-blade segments of the n-th stage stator blade and the stator-blade segments (17;13) of the (n+1)-th stage stator blade (7;3) is set to zero or to five or more, and/or a blade-count difference between the rotor-blade segments (15;11) of the n-th stage rotor blade (5;1) and the rotor-blade segments of the (n+1)-th stage rotor blade is set to zero or to five or more, and wherein a relative position between the n-th stage stator blade and the (n+1)-th stage stator blade (7;3) in the circumferential direction is set such that a wake flow produced by the stator-blade segments of the n-th stage stator blade is guided to a ±1/4 pitch region in the circumferential direction with respect to a leading edge of each stator-blade segment (17;13) of the (n+1)-th stage stator blade (7;3) and within a range of 0% to 15% and/or a range of 85% to 100% of the length in a span direction from a hub side of the stator-blade segment (17;13) of the (n+1)-th stage stator blade (7;3), one pitch being equal to a distance between adjacent stator-blade segments (17;13) in the circumferential direction.