A turbine housing for a turbocharger of a twin-scroll type, comprising: a turbine shaft housed in the turbine housing; a partition wall formed in the housing; and two scroll passages (42,44), divided by the partition wall, including a front scroll passage and a rear scroll passage formed on a front side and a rear side respectively in the turbine housing, through the scroll passages (42,44) exhaust gas flowing from outside toward inside in a radial direction and then flowing in an axial direction of the turbine shaft to be discharged, the front side being an exhaust exit side and the rear side being a bearing housing side, wherein a front wall of the front scroll passage curves toward the front side from the inside toward the outside in the radial direction so as to secure cross-sectional areas of the front scroll passage and the rear scroll passage, wherein a root part of the partition wall curves toward the front side in correspondence with the front wall so that the cross-sectional area of the front scroll passage equals to the cross-sectional area of the rear scroll passage, wherein the cross-sectional areas of the front scroll passage and the rear scroll passage gradually decrease from the outside toward the inside in the radial direction and a tip part of the partition wall is arranged in a direction perpendicular to a leading edge of a turbine rotor blade so that the front scroll passage and the rear scroll passage are symmetrical near the tip part with respect to an axis of the tip part, characterized in that a rear wall of the rear scroll passage of the turbine housing projects perpendicular to a center axis of the turbine shaft. a turbine shaft housed in the turbine housing; a partition wall formed in the housing; and two scroll passages (42,44), divided by the partition wall, including a front scroll passage and a rear scroll passage formed on a front side and a rear side respectively in the turbine housing, through the scroll passages (42,44) exhaust gas flowing from outside toward inside in a radial direction and then flowing in an axial direction of the turbine shaft to be discharged, the front side being an exhaust exit side and the rear side being a bearing housing side, wherein a front wall of the front scroll passage curves toward the front side from the inside toward the outside in the radial direction so as to secure cross-sectional areas of the front scroll passage and the rear scroll passage, wherein a root part of the partition wall curves toward the front side in correspondence with the front wall so that the cross-sectional area of the front scroll passage equals to the cross-sectional area of the rear scroll passage, wherein the cross-sectional areas of the front scroll passage and the rear scroll passage gradually decrease from the outside toward the inside in the radial direction and a tip part of the partition wall is arranged in a direction perpendicular to a leading edge of a turbine rotor blade so that the front scroll passage and the rear scroll passage are symmetrical near the tip part with respect to an axis of the tip part, characterized in that a rear wall of the rear scroll passage of the turbine housing projects perpendicular to a center axis of the turbine shaft.