To solve the problem that the control of an infrared ray generation circuit and an ultrasonic wave generation circuit cannot be certainly carried out, since a power supply circuit starts operation when a tip of an electronic pen is contacted to a medium, and stops the operation when the tip of the electronic pen is separated from the medium, in other words, a control circuit repeats start and halt of the operation each time when the tip of the electronic pen repeats the contact or separation to/from the medium, and especially if the control circuit is a microcomputer, an initialization operation is repeated frequently.

A power supply voltage generation circuit includes; a power supply circuit which generates power supply voltage; a switch for starting at least operation of the power supply circuit; and a control circuit which starts operation by being supplied with the power supply voltage from the power supply circuit and performs control for continuing the operation of the power supply circuit for predetermined time regardless of a status of the switch.