To improve turbine efficiency by suppressing leakage from a side clearance.

In each variable nozzle vane 24, a throat constitution part 30 constituting a throat part 28 having a minimum cross section of a communication flow passage 26A is provided between the variable nozzle vane 24 and an adjacent upstream variable nozzle vanes 24A in the flowing direction of a scroll passage 18, and shapes of upper and lower faces 36, 37 of each variable nozzle vane 24 are set so that a difference of static pressure between the upper face 36 positioned on the adjacent downstream variable nozzle vane 24B side in the flowing direction of the scroll passage 18 and the lower face 37 positioned on the adjacent upstream variable nozzle vane 24A side is set smaller on the scroll passage 18 side and a turbine chamber 16 side with respect to the throat constitution part 30 than that in the throat constitution part 30. In each side wall part 42 on both sides of the throat constitution part 30 having larger static pressure between the upper face 36 and the lower face 37, a rotating shaft part 44 is provided.

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