This invention enables the full-body (throughout the entire thickness) scribing of a plate made of fragile material such as glass by irradiating the work with the laser beam for heating with or without cooling and thereby generating the tensile thermal stress in the work which exceeds the cleavage toughness of the material, dispensing with the mechanical breaking. In this invention, the absorption of the beam in the work is so controlled that the beam, while being absorbed in it, is either transmitted through it or reaches the adequate thickness of the work and the entire thickness scribing is realized. This absorption control is done by selecting the laser beam wavelength so as to achieve the proper absorption in the absorption spectra of the material either due to the electronic transition or the lattice vibration. The doping of the material, in which the commercially available high power laser beam can be absorbed properly and either of the absorption or emission in the visible light spectral range does not exist, can also be utilized for this absorption control. In this case, the quenching of the fluorescence which may arise after the beam absorption is useful. This invention enables the profile scribing of work or the selective scribing of piled work consisting of plural number of plates.