A plasma generation apparatus includes a flow path tube through which a liquid flows and which includes a concave portion and/or a convex portion on an internal wall surface thereof, a liquid feed device, a first electrode, a second electrode, a power source, and a control circuit which controls the liquid feed device and the power source. The concave portion and/or the convex portion causes, when the liquid flows therethrough, a pressure difference to be generated between at least part of the inside of the flow path tube and the external space, allowing a gas to be introduced into the liquid from the external space through a gas introduction path. The power source applies a predetermined voltage between the first electrode and the second electrode in a state in which a bubble containing the gas is generated in the liquid.