A laser surgical device for vaporization of a living tissue consists of an operating laser assembly, a detecting arrangement and a control unit. The operating laser assembly generates an operating beam having a predetermined wavelength corresponding to a peak absorption wavelength of water. The detecting arrangement is adopted for detecting a condition of an operated living tissue by receiving and reviewing a signal reflected from the operated living tissue so as to produce a control signal. The control unit controls characteristics of the operating beam based on the control signal, so that the depth of vaporization of the living tissue does not exceed 15-20 microns.
