To provide a DC pulse generating device capable of preventing the adhesion of shells to a channel communicated with an intake port and a discharge port of sea water and devices arranged near the channel.

This device is provided with an AC power supply E1, a high- voltage transformer TR1, a rectifying circuit D1, a charging thyristor SCR1, a capacitor C1, a discharging thyristor SCR2, a coil L1, a plurality of electrodes 1a, 1a' arranged at constant intervals and connected to the output side of the coil L1, a resistance measuring means measuring the sea water resistance value between the electrodes 1a, 1a', and a control circuit 5 feeding the gate voltage to the charging thyristor SCR1 and discharging thyristor SCR2 to change the voltage value applied between the electrodes 1a, 1a in response to the resistance value measured by the resistance measuring means, controlling the on/off of the thyristors SCR1, SCR2, and controlling the charging voltage value to the capacitor C1 and the charging/discharging timing of the capacitor C1.