To improve the stability of pulse laser processing, by using only the pulses having energy within a prescribed range.

A pulse laser device is provide with a feed-forward control system. According to the system, a pulse of laser beam emitted from a pulse laser generator 1 is split by a beam splitter 2 to separate part of the laser beam as a beam of inspection light, whose energy is detected by a photodiode 3. Then, at a projection determining circuit 4, appropriateness of projection of the laser beam is determined. The inspection light is isolated and is subjected to laser energy detection for each pulse of laser beam; and only the pulse of laser beam having energy within a given range is counted by a counter circuit 5 and is projected from an EOM (electro-optical modulator).