The instrument of the present invention irradiates a relatively large skin area evenly with laser beams. A plurality of semiconductor laser diodes are arranged to form two lines with the semiconductor laser diodes of one line staggered with those of the other line, and the semiconductor laser diodes of each line are so inclined that their laser beams may focus on a single line. With this arrangement the plurality of laser beams provide a linear distribution of narrow beam, and the scanning area on the skin can be expanded accordingly. The beauty treatment on the skin or the depilation treatment can be expedited significantly. Advantageously the focusing points of the laser beams are distributed at an increased density, and the irradiation strength averages everywhere to attain the even beauty treatment.
A laser depilating method for depilating treatment by irradiating a skin surface with a laser beam emitted from a semiconductor laser. A treatment region of the skin surface is treated with a semiconductor laser beam for an irradiation time of 100 msec or more per irradiation while controlling the laser beam so that the energy density when irradiating the skin surface may be in a range of 0.01 1 J/mm.sup.2. Irradiation of the skin surface with a semiconductor laser beam under such a condition provides a more secure and efficient treatment effect of laser depilation. A plurality of semiconductor laser beams are used as necessary to irradiate a wider area of skin surface at a time.
