A jet nozzle apparatus includes a hose having a faucet connection member to be connected to a faucet of a hot-water supply system or a hot-water supply unit, a mixing unit for mixing compressed hot water introduced through the hose with air, and a nozzle, connected to the hose, for forcibly jetting out a fluid mixture of hot water and air. A fluid mixture of hot water and air can be jetted out in an arbitrary direction by using the nozzle.