The temperature distribution and evolution of metal field‐ion emitters under pulsed and continuous‐wave (cw) laser irradiation are obtained numerically using implicit alternating direction method. For the cw laser irradiation, the temperature distribution in the emitter reaches a steady‐state value after approximately 2 &mgr;s of laser heating. The peak temperature of the tip apex reached depends almost linearly on the incident energy flux of the laser beam, and also on the cone angle of the emitter. For the fast laser pulse, both the waveform and the spatial intensity variation of the laser beam are considered. The numerical result is found to differ only slightly from that obtained by assuming a square shape of the laser pulse. The feasibility and advantages of using a laser beam as a means of heating the emitter in the study of single atom surface diffusion and adatom‐adatom interaction, laser‐induced silicide interface formation, and other studies with the Atom Probes and Field Ion Microscope are also discussed.