PURPOSE: To obtain a mechanical sensor in which the range for sustaining the reversibility is widened while suppressing the fluctuation of temperature characteristics and the early fatigue.

CONSTITUTION: The mechanical sensor for measuring the displacement, deformation or distortion of an object through deformation of itself is made of a polymer film. The film has a conductive upper part A and a lower part B of insulator. The mechanical sensor is deformed when it is imparted with a distortion to cause variation of resistance at the upper part A and the distortion can be measured based on the variation of resistance. A thermally stable polymer is preferably employed.