The purpose of this research was to determine mechanical strength of thin evaporated metal films by a centrifuge method. It is known that the tensile strength of thin films increases as thick n ess decreases. If the thickness of thin film is reduced from about 6 x 10-S centimeters. to 2 x 10- 5 centimeters, the tensile strength increases many times if the dislocations can be removed completely or locked in the surface so they cannot move.