Maintaining consistent power level is important factor in laser micromachining because amount of ablation material depends on laser fluence, which is the laser energy per unit time and surface area. This research aims to find out method of laser power stabilization for laser micromachining. Initially, two kinds of lasers are selected and power stabilization is tested with various power levels. Using optical attenuator which consisting the half-wave plate, the linear polarizer and the PID controller using Labview flame is set up for the laser power stabilization system. it advantages is simple and most laser source is able to apply. Then designed power stabilization system is tested with two kinds of laser source 1064nm fiber laser and femto second laser. then laser power fluctuation is 0.04% at 1064nm fiber laser and 0.2% at femto second laser. It is similar performance with commercial power stabilization system. Finally, we tested Si wafer processing with power stabilization system. Experimental result was improved machining accuracy.