A semiconductor laser apparatus has a Zener diode containing a first semiconductor region of a first conduction type and a second semiconductor region of a second conduction type joined with the first semiconductor region, and a vertical-cavity surface-emitting semiconductor laser diode stacked above the Zener diode and containing at least a first mirror layer of a first conduction type, a second mirror layer of a second conduction type and an active region sandwiched between the first and second mirror layers. The first semiconductor region and the second mirror layer are electrically connected and the second semiconductor region and the first mirror layer are electrically connected.