A laser diode device capable of detecting laser light with a simple structure is provided. A laser diode device, includes a semiconductor layer formed through laminating a first conductive type layer, an active layer and a second conductive type layer in this order, the second conductive type layer including a striped current confinement structure in a top portion thereof, and a plurality of electrodes being formed on the second conductive type layer side of the semiconductor layer and being electrically connected to the second conductive type layer at predetermined intervals, wherein the semiconductor layer has a photoreceptor region in a region corresponding to an electrode (a first electrode) of the plurality of electrodes except for at least one, the photoreceptor region absorbing a part of the light emitted in the semiconductor layer to convert the part of the light into a current signal.