PURPOSE: To shorten the inspecting time and to improve the inspection precision by a method wherein the characteristics of the laser diode are inspected, keeping the laser diode as it is in a state of bar.

CONSTITUTION: A laser diode bar 7 is constituted of plural pieces of laser diode elements 1, top electrodes 2 isolated in each element 1, a bottom electrode 3 common to each element 1 and a reflective surface 4 having light-emitting region parts 5, which amplifies generated light and emits laser beams 8. The bar 7 is fixed on a stage 16, whose surface consists of a good conductor, by sucking with a suction hole 20. A probe 19a for inspection is made to contact with the top electrode 2 of the element 1, while the other probe 19b is made to contact with the surface of the stage 16 and current is flowed, each element 1 is made to emit light and laser beams 8 are detected by a sensor 17 and inspected.