A turbine casing includes: a shroud of a cylindrical shape defining an operational flow path between the shroud and a hub of a turbine rotor; a scroll outer peripheral wall continuing from an end side of the shroud and extending along a circumferential direction of the shroud; and a partition wall disposed inside the scroll outer peripheral wall and dividing an inside of the scroll outer peripheral wall into a first scroll flow path and a second scroll flow path disposed adjacent to each other in an axial direction of the shroud. The shroud, the scroll outer peripheral wall, and the partition wall are formed integrally by casting. The partition wall has a widening section which partially increases a communication area between at least two of the first scroll flow path, the second scroll flow path, and the operational flow path, in the circumferential direction of the shroud.
