On a two-shaft gas turbine, on at least one of an inner peripheral side or an outer peripheral side of a main flow passage, an outlet of a high-pressure turbine is lower than an inlet of a low-pressure turbine, an outer periphery of a flow channel that connects the outlet of the high-pressure turbine and the inlet of the low-pressure turbine includes a first casing shroud that is supported by a casing and located on an outer peripheral side of a final-stage rotor vane of the high-pressure turbine, and an initial-stage stator vane of the low-pressure turbine, and a connection position of the first casing shroud and the initial-stage stator vane of the low-pressure turbine is closer to the inlet of the initial-stage stator vane of the low-pressure turbine than the outlet of the final-stage rotor vane of the high-pressure turbine.