A liquid treatment apparatus includes a housing for storing a liquid, a first electrode at least part of which is arranged in the housing, a second electrode, a third electrode, a first power supply that, in operation, applies a first voltage between the first electrode and the second electrode to make the first electrode held effectively positive with respect to the second electrode, and a second power supply that, in operation, applies a second voltage between the second electrode and the third electrode to make the third electrode held effectively negative with respect to the second electrode. Plasma is generated inside a bubble, which is present in the liquid, when the liquid is stored in the housing and the first power supply applies the first voltage between the first electrode and the second electrode.