The method comprises cutting workpieces (1) from a board (2) of monocrystalline silicon by laser cutting process, heating the cut workpieces at a temperature of 400[deg] C and exposing to a gas atmosphere containing oxygen and/or nitrogen so that a surface of the workpiece is oxidized and/or nitrated in an area of the cut surface using a pulsating plasma, treating the surface of the workpieces in the area of the cut surface with a chemical composition through which the oxidized or nitrided fraction of the surface is removed, and partially coating the surface of the workpieces. The method comprises cutting workpieces (1) from a board (2) of monocrystalline silicon by laser cutting process, heating the cut workpieces at a temperature of 400[deg] C and exposing to a gas atmosphere containing oxygen and/or nitrogen so that a surface of the workpiece is oxidized and/or nitrated in an area of the cut surface using a pulsating plasma, treating the surface of the workpieces in the area of the cut surface with a chemical composition through which the oxidized or nitrided fraction of the surface is removed, and partially coating the surface of the workpieces in the region of the cut surface. The cutting of the workpiece is effected by a pulsed laser, where a pulse energy of the laser is 50 mu m. The board of monocrystalline silicon is attached on a support before cutting the workpiece, a frame (7) is removed from the support after cutting the workpiece, and then the workpiece remains on the support for oxidizing or nitriding. An independent claim is included for a plant for producing micromechanical workpieces from a board of monocrystalline silicon.