The two-dimensional integral Laplace transform technique has been applied to get the temperature distributions in the molten layer, the solid part and in the backward surface of a finite target irradiated with a pulsed laser. Formulas for the time dependence of the evaporated part and the molten layer thicknesses of the target were found. This is accomplished by considering the temperature dependence of the absorption coefficient of the irradiated surface as well as the chemical reaction. As an illustrative example computations were carried out on an aluminum (Al) target.