Specifies a standard test piece, which is used to guarantee the propriety and accuracy of a tensile testing system for thin film materials with length and width under 1 mm and thickness under 10 m, which are main structural materials for microelectromechanical systems (MEMS), micromachines and similar devices. It is based on such a concept that a tensile testing system can be guaranteed in propriety and accuracy, when the measured tensile strengths of the standard test pieces, whose tensile strength is pre-determined, are within the designated range. It also specifies the test pieces to minimize characteristics deviation among the pieces.