Provided is an ultrafine bubble generating apparatus capable, when generating nanobubbles in a liquid, of appropriately mixing a gas into a liquid ejected from a liquid ejector. The ultrafine bubble generating apparatus includes a liquid ejector for ejecting a liquid, a gas mixer for pressurizing and mixing a gas into the liquid ejected from the liquid ejector, and an ultrafine bubble generator for generating nanobubbles in the liquid by passing the liquid with intermixed gas therethrough. Between the liquid ejector and the ultrafine bubble generator, the gas mixer pressurizes and mixes the gas into the liquid, which is flowing in a pressurized state toward the ultrafine bubble generator.