A gas turbine includes a nozzle vane and a sealing unit engaged with the nozzle vane inside a turbine supplied with combustion gases produced by mixing and burning air for combustion and fuel. The nozzle vane and the sealing unit are disposed in a channel of the downward flowing combustion gases on the outlet side of a gas path. A plurality of engagement portions between the sealing unit and the nozzle vane are provided successively from the upstream side toward the downstream side in a direction of flow of the combustion gases, and a downstream one of the plurality of engagement portions has a contact interface formed in a direction across a turbine rotary shaft. A reduction in the thermal efficiency of the gas turbine can be suppressed.