Summary form only given, as follows. In the analysis of laser machining mechanisms that have been carried out to date, the central feature is use of the conduction equation of Fourier to describe the way in which photon energy from the laser beam is transferred to the atomic lattice of the target material. It is this energy transfer mechanism that defines the laser-metal interaction process. It is of the greatest importance in the analysis of laser machining of materials to specify accurately the surface temperature of the irradiated material since material removal rates are closely related to evaporation rates and absorption is essentially a surface phenomenon. The present study examines the validity of the Fourier heat conduction mechanism taking place during laser heating of metals. The assumptions made in the Fourier theory are discussed in detail, it is found that the heat conduction mechanism must be examined on a microscopic level.