In recent years,the heat-assisted magnetic recording is suggested as the key-technology to achieve the recording density of more than lTb/in^2.In this technology,It may be problem for the depletion of lubricant film to occur by the laser irradiation,because that is heated to high temperature with laser beams.In this study,we focused on the thermal stability of the lubricant film with the different adsorption states on magnetic disks by the laser irradiation.As a result,it was found that the depletion of lubricant films by laser irradiation showed a different behavior from the reduction of lubricant thickness after heat treatment.The lubricant film with only chemical bonding showed lowest depletion by the laser irradiation