PROBLEM TO BE SOLVED: To provide a plasma irradiation device in which, by applying a device for generating mild plasma such as glow-type one produced through dielectric-barrier discharge or the like, a thermal load is extremely low with a low-temperature plasma, and operability and safety are good, and loads to a living body are reduced.SOLUTION: The plasma irradiation device includes one or more ducts made of an insulating material such as dielectric bodies for the supply of gas, electrodes covered by insulating materials such as the dielectric bodies for the supply electric power, and a discharge chamber formed with the dielectric bodies for installing the one or more ducts and electrodes. The plasma irradiation device is provided with a mechanism to diffuse the gas in its introduction hole to the discharge chamber, has ground electrodes installed outside the discharge chamber, generates the plasma by discharging the gas detained in the discharge chamber, and jets out the plasma through nozzles installed in the discharge chamber. The plasma irradiation device is featured in once detaining the gas and plasma within the discharge chamber, and then jetting out the plasma from there.
