PURPOSE: To improve the assembling property of the titled wrist watch, by providing a support frame independently having a cell receiving part for receiving an electronic optical display cell and a sensor receiving part for receiving an optical sensor which is, in turn, mounted in said sensor receiving part of the support frame through a spacer.

CONSTITUTION: An optical sensor 30 is formed by providing a solar cell 32 made of amorphous silicon to the under surface of a transparent glass substrate 31 while applying a protective coating due to epoxy resin 33 to the element part thereof and a positive electrode part 33a and a negative electrode part 32b are formed to both end parts of the glass substrate 31 from an ITO film while a discriminating mark 32c for discriminating positive/negative property of the electrode is formed to the positive electrode part 32a by metal vapor deposition.