Electric discharge device and electrode device

An electric discharge device comprising:

• a columnar discharge electrode;
• a counter electrode facing the columnar discharge electrode;
• a voltage application circuit that generates discharge by applying an application voltage between the columnar discharge electrode and the counter electrode;
• and
• a liquid supply unit that supplies liquid to the columnar discharge electrode, wherein:
• the liquid extends and contracts along a central axis of the columnar discharge electrode by the discharge generated by the voltage application circuit,
• the counter electrode includes:
• a peripheral electrode part that protrudes to a side opposite to the columnar discharge electrode and includes an opening portion formed in a distal end surface of the peripheral electrode part;
• an extending part extending outward from the peripheral electrode part and including an annular shape groove;
• a flat plate part connected to the extending part;
• and
• a projecting electrode part projecting from the peripheral electrode part into the opening portion,
• when the liquid is extended, a tip of the liquid is located between the columnar discharge electrode and a position corresponding to an outer peripheral edge of the peripheral electrode part, inclusive, in a view along a central axis of the columnar discharge electrode,
• the annular shape groove includes an inner portion connected to the peripheral electrode part and an outer portion connected to the flat plate part,
• the outer portion is formed so as to be farther from the columnar discharge electrode in the direction along a central axis of the columnar discharge electrode as the outer portion is farther from the peripheral electrode part, and
• the inner portion is formed so as to be closer to the columnar discharge electrode in the direction along the central axis of the columnar discharge electrode as the inner portion is closer to the peripheral electrode part.