In this paper, we study laser processing on silicon nitride(Si3N4) material using femtosecond laser and nanosecond laser. It is aimed to investigate ablation characteristic with various laser process conditions, such as laser average power, machining speed, machining times, Roughness and hole tapering. The quality of ablated surface of the silicon nitride was evaluated with microscope and roughness measuring instrument. Nanosecond laser occur heat affect zone. But femtosecond laser not occur heat affect zone. In addition, tapering can be reduced by optimizing the machining path and edge roundness can be improved.