To provide a portable cutting machine which performs a cutting work with excellent operability along a marking-off line without being affected by cutting dust generated from a rotary cutter by irradiating laser beam for marking on a virtual straight line moved in parallel in a lateral direction from an actual cutting line by the portable cutting machine.

This machine is provided with a light beam irradiating device 7 for irradiating one or more laser light beams 11 for marking or a laser light beam 11 for marking of a straight line on a line parallel to an extended line 9 of a cutting direction of the rotary cutter 2.