In this work there are shown results of the complex theoretical and experimental investigation of laser dimensional treatment of different types of carbon plastics with the thickness of 1mm with the matrix on the base of thermosetting binding agents. In the course of this work fulfillment there was developed an experimental plant on the basis of a pulse nano-second fiber laser of type YLPM-1-4x200-20-20 with the wave length of 1.06 µm and average radiated power of 20 W. The theoretical assessment of a thermal impact area is carried out on a model of an instantaneously operating normally distributed circular source on the surface of a semi-infinite body. In accordance with the assessment given there are formulated recommendations for a choice of definite technological parameters of machining conditions directed to the decrease of a thermal impact area and increase of processing speed. In the course of experimental researches a laser source operated with a maximum average power, beam scanning was carried out by a two-axial galvano-scanner. The experiments were carried out without technological gas supply in are environment at different speeds of beam scanning, laser operating modes, passes number, hatch distances and positions of a focusing plane. The area of a thermal impact and geometry of a cut slot were analyzed with the aid of an optic and electronic microscope and a contour-graph. The work result is recommendations for a choice of technological parameters and an algorithm of processing at which the area of thermal impact is less than 150 µm; taper of a cut slot is less than 100 µm; there are no defects on a surface and a cross profile of the cut slot section; a high speed of processing is achieved.