Abstract: A jet injection device that incorporates nanobubbles (ultrafine bubbles) in a mist includes: a two-fluid nozzle configured from a circular nozzle outer cylinder and an air connection tube integrally and perpendicularly connected to the nozzle outer cylinder; a nanobubble generation device that supplies the nozzle outer cylinder of the two-fluid nozzle with high-pressure nanobubble water; and a compressor that supplies the air connection tube of the two-fluid nozzle with high-pressure air. The gas-injected bubble water generated from the nanobubble generation device is pressure-fed to the nozzle outer cylinder of the two-fluid nozzle, and compressed air from the compressor is pressure-fed to the air connection tube of the two-fluid nozzle. In the two-fluid nozzle, the high-pressure gas-injected bubble water and the compressed air serve as a gas-liquid fluid mixture, and are injected at a high speed in mist form from a nozzle cylinder of the two-fluid nozzle.