TURBINE HOUSING AND SUPERCHARGER

This turbine housing comprises an inlet-side casing including a scroll part having therein a scroll flow passage, an outlet-side casing fastened to the inlet-side casing, and a flow passage forming member which includes a flow passage wall surface for demarcating an exhaust gas flow passage that guides exhaust gas from the scroll flow passage to a turbine wheel and which is fastened to the outlet-side casing. The outlet-side casing includes a cylindrical part that has therein an outlet flow passage through which flows the exhaust gas having passed the turbine wheel; a flange part that protrudes to a radial outside from the downstream-side end section of the cylindrical part and is fastened to the scroll part by a first fastening member; and an annular plate part that protrudes to a radial outside from the upstream-side end section of the cylindrical part and is fastened to the flow passage forming member by a second fastening member, wherein the annular plate part has at least one recess section recessed from an outer peripheral end to a radial inside.