When an electronic timepiece is in a power-saving mode in which the current time display is suspended, it is determined whether or not the charge voltage supplied from a high-capacity capacitor is higher than a predetermined reference voltage, and if higher, enough electrical energy is stored in the high-capacity capacitor to return from the power-saving mode to the display mode, so that a current time restoration process is performed upon detecting power generation. On the other hand, if the charge voltage is less than or equal to the predetermined reference voltage, the supply of the power supply voltage to the control circuits is stopped to prevent the electrical energy stored in the high-capacity capacitor from being consumed needlessly. As a result, the electronic timepiece can be reactivated quickly when the power generating device begins to generate power.