In this paper the digital pulsed power system to supply a very small repetitive Mather-type Plasma Focus Device (20 J) is presented. The structure of this electrical system included a pulsed power supply and a Microcontroller based control system. In Plasma Focus Devices a dc power supply charges a high voltage capacitor and then this saved energy discharges between two coaxial electrodes using a controllable spark gap switch. The procedure of control the capacitor charging and discharging are explained in this paper. Finally, the experimental results of electrical discharge and pinch shaping in plasma focus in different working conditions are presented and a good repetitive performance in a wide domain of working conditions is seen.