PURPOSE: To make it possible that the user compensates the difficulty in seeing liquid crystal pulses by inputting the signal from an external operation member to a liquid crystal driving voltage varying circuit to adjust a liquid crystal driving voltage with a manual operation.

CONSTITUTION: A signal 6 from an external operation member 1 is inputted to a liquid crystal driving voltage varying circuit 2 consisting of a base voltage varying part 9, a voltage comparing part 10, and a buffer part 11, and a liquid crystal driving circuit 3 is operated by an output voltage 7 of the circuit 2 to adjust the contrast of a liquid crystal plane 4. The external operation member 1 is connected to a time counting circuit 5 to constitute a clock function. By this constitution, the contrast is adjusted at an optional time in accordance with the subjectivity of the user. The liquid crystal driving voltage is changed by the operation of a button or the like, and troubles are not generated with respect to design and waterproof property. Since the liquid crystal driving voltage is generated by a resistance division ratio, the low contrast of the display of the liquid crystal due to the lowering of the power source voltage of the watch is compensated.