Liquid processing apparatus including container, first and second electrodes, insulator surrounding at least part of side face of the first electrode, gas supply device, metallic member surrounding part of side face of the first electrode, and power source
A liquid processing apparatus includes a container for holding liquid, a first electrode, a second electrode, a first insulator that has a cylindrical shape and at least partly surrounds a side face of the first electrode via a space, the first insulator having an opening in an end face of the first insulator, a gas supply device that supplies gas into the space and releases the gas into the liquid via the opening, a power source that applies a voltage between the first electrode and the second electrode and generates plasma, and a metallic member that partly surrounds the side face of the first electrode via the space. The metallic member is electrically connected to the first electrode. At least a part of the first insulator is disposed between the first electrode and the metallic member.