Cooled turbine blade for a gas turbine

A cooled turbine blade provided on a turbine rotor of a gas turbine including pressure side cooling flow passages and suction side cooling flow passages extending in a span direction and formed in said gas turbine blade, said pressure side cooling flow passages and said suction side cooling flow passages being connected together to form a series cooling flow passage assembly, said pressure side cooling flow passages conducting a cooling medium in a direction from a root of said turbine blade toward a tip portion of said turbine blade, said suction side cooling flow passages conducting said cooling medium in a direction from said tip portion of said turbine blade toward said root of said turbine blade, said turbine blade comprising:

• at least one of said suction side cooling flow passages forming the most downstream cooling flow passage;
• said most downstream cooling flow passage having a root side end portion communicating with a root side end portion of one of said suction side cooling flow passages which is at an upstream side of said most downstream cooling flow passage, said cooling medium flowing from said tip portion toward said root in said suction side cooling flow passage at said upstream side of said most downstream cooling flow passage, and flowing from said root toward said tip portion in said most downstream cooling flow passage;
• and
• said most downstream suction side cooling flow passage communicating with an outside of said turbine blade through film cooling nozzles, for exhausting said cooling medium flowing from said root toward said tip portion in said most downstream flow passage through said nozzles.