This International Standard specifies the method for axial tensile?Ctensile force fatigue testing of thin film materials with a length and width under 1 mm and a thickness in the range between 0@1 ?? and 10 ?? under constant force range or constant displacement range. Thin films are used as main structural materials for MEMS and micromachines. The main structural materials for MEMS@ micromachines@ etc.@ have special features@ such as typical dimensions of a few microns@ material fabrication by deposition@ and test piece fabrication by means of non-mechanical machining@ including photolithography. This International Standard specifies the axial force fatigue testing methods for micro-sized smooth specimens@ which enables a guarantee of accuracy corresponding to the special features. The tests are carried out at room temperatures@ in air@ with loading applied to the test piece along the longitudinal axis.