The object is to provide a method and device to detect internal defect in the weld overlaid portion of erosion resistant material in the border portion between the blade profile and the shroud of a turbine blade with high accuracy by a static test method for an individual turbine blade applying a resultant pressing force, corresponding to centrifugal force and untwisting force of the turbine blade 10 in operation of the turbine, to the shroud 12 with installing the blade root 18 of the turbine blade 10 to the blade root retainer 20 and applying a force in the direction of centrifugal force on the blade root 18 from outside of the blade root retainer 20 to eliminate backlash between the blade root 18 and blade root retainer 20, retaining securely the shroud 12 on the side opposite to the portion which is applied the pressing force, and implementing simulated test of centrifugal stress in the weld-overlaid portion by applying the resultant pressing force, corresponding to centrifugal force and untwisting force of the turbine blade 10 in operation of the turbine, to the shroud 12.