Liquid treatment apparatus including first electrode, second electrode, and first and second insulators surrounding lateral surface of first electrode

A liquid treatment apparatus comprising:

• a vessel for storing a liquid;
• a first electrode;
• a second electrode at least a part of which is arranged inside the vessel;
• a first insulator having a tubular shape and a first opening at an end of the first insulator, the first insulator surrounding a lateral surface of the first electrode with a first space interposed between the first insulator and the lateral surface of the first electrode;
• a second insulator having a tubular shape, the second insulator surrounding the lateral surface of the first electrode;
• a gas supply device that supplies gas into the first space and ejects the gas into the liquid through the first opening;
• and
• a power supply that applies a voltage between the first electrode and the second electrode and produces plasma, wherein:
• the first insulator surrounds the second insulator,
• the second insulator is arranged with a second space interposed between the first insulator and the second insulator,
• the first opening of the first insulator is arranged to be in contact with the liquid when the liquid is stored in the vessel, and
• a portion of the first electrode, which is positioned inside the vessel, and a portion of the second insulator, which is positioned inside the vessel, are covered with the gas when the liquid is filled in the vessel and the gas is supplied into the first space by the gas supply device.