oscillating means having a capacitor for protecting from a current leakage in an oscillation circuit loop for outputting a signal of a predetermined frequency;

dividing means for dividing the output signal from the oscillating means and outputting a timepiece signal constituting a reference of a time counting operation;

driving means for outputting a drive signal based on the timepiece signal outputted from the dividing means;

displaying means driven by the drive signal for displaying current time;

drive power supplying means for supplying a drive power at least to the oscillating means; and

controlling means for controlling the drive voltage outputted from the drive power supplying means;

wherein the oscillating means includes switching means; and

wherein the controlling means controls the switching means to short-circuit the capacitor in order to generate noise constituting a trigger in starting to oscillate the oscillating means and electrically insert the capacitor into the oscillation circuit loop after an elapse of a predetermined time period, and the controlling means controls the drive power supplying means to supply a power source voltage to the oscillating means as the drive voltage in starting to oscillate the oscillating means, and to supply a voltage within a predetermined range lower than the power source voltage and a voltage pulsating by a predetermined period from the drive power supplying means to the oscillating means by intermittently controlling to drive the drive power supplying means by the predetermined period after an elapse of a predetermined time period from starting to oscillate the oscillating means.