Herein, r,2 is the radius of the conducting channel, r,2 << r.1 and r13, and the outside radius of all sections are equal, A multi-gap multi-channel(MGMC) switch of 500 ro1 = ro2 = rO3, the inductance of the entire spark gap is, kV has been developed at Pohang Accelerator Laboratory therefore, approximately (PAL). It consists of ten of gaps to increase self-discharge voltage by filling up the gas. A structure of a multi-gap L _ FrO2 1(2) switch can increase its inductances. Thus, in order to sg a 2-7 * L >r ( solve those problems its structure made by multi-channels 2 had been designed to decrease the inductance effects. The where La iS the arc channel inductance. The small arc fabricated switch tested using marx generator of 500 kV. channel diameter results in a relatively large inductance,The design concept and its characteristics will be nearly independent of the external conductor geometries.discussed. For this reason, multiple, parallel arc channel spark gaps are commonly used to increase the effective radius of