Abstract: For single-use and cost-effective pulsed power system such as exploding foil initiators, a micro planar gas spark switch is designed and fabricated based on microfabrication. The size of the switch is only about 1.5 cm0.5 cm. Device testing of the switch gives an output of peak current 3 450 A and rise time 164 ns, which satisfies the demand of exploding foil initiators and ordinary pulsed power systems. System modeling based on experimental data shows that the inductance and resistance of the switch circuit are 26.5 nH and 0.066 , respectively. Compared with the conventional stereo spark gap switch, the parameters of the device are greatly optimized.