There is provided a laser driving circuit having a small circuit scale which is capable of low voltage operation and in which unnecessary writing in an optical disc, or the like, is entirely prevented. To this end, the laser driving circuit includes a source-grounded amplifier to which the supply voltage of the first power supply is supplied as well as to a laser driving circuit block and to which the voltage of the second power supply of a control circuit block is input. A bias input terminal of a differential amplifier is pulled up according to an output of the source-grounded amplifier till the voltage of the second power supply rises, whereby an output of the laser driving circuit block is suppressed. With such a structure, unnecessary emission of a semiconductor laser, breakage of the semiconductor laser, etc., are prevented.