Abstract: A discharge circuit for pulsed laser 10 in which one connecting portion of a preionization capacitor Cpp is connected to a preionization electrode 4 and the other one connecting portion of the preionization capacitor Cpp is connected to a junction between a capacitor C2 and a magnetic switch AL2. In the discharge circuit for pulsed laser 10, a voltage Vcc of the preionization capacitor Cpp, which is charged in synchronization with the charging of the capacitor C2, increases at a time t3 earlier by a predetermined time than a start time t6 of main discharge by the main discharge electrodes 1, 2. When a voltage of the preionization electrode 4 increases to a predetermined preionization start voltage through the preionization capacitor Cpp, a main discharge gap 3 is preionized by a corona discharge caused by the preionization electrode 4 and the main discharge is caused by the main discharge electrodes 1, 2 with the main discharge gap 3 fully preionized.

Abstract: A peaking capacitor layout in which a discharge energy is not lowered even when peaking capacitors are decreased in their capacitance, increased in their number and disposed in a plurality of rows. The discharge energy is uniformly distributed to obtain a stable laser power. A peaking capacitor group in a first row formed of a plurality of peaking capacitors and a peaking capacitor group in a second row formed of a plurality of peaking capacitors are disposed in a plurality of rows (two rows) in a direction in which a length of a loop changes. The capacitance of the peaking capacitors forming the second row having a long loop is adjusted to be smaller than that of the peaking capacitors forming the first row having a short loop. And, the capacitance of the peaking capacitors in the first and second rows are adjusted so that the distribution of the capacitance of the peaking capacitors becomes uniform along the longitudinal direction of the discharge electrodes.