To provide a two-fluid nozzle for cleaning which enables an attempt of reducing the amount of a high-pressure gas used while retaining advantages of high cleaning effect and efficiency and very little damage on articles.

The two-fluid nozzle spraying a liquid mist flow from a spraying outlet to impact the flow on an article to be cleaned and has a gas-liquid mixing section mixing a high-pressure gas with a high-pressure liquid to form liquid mist, a gas-introducing section introducing a high-pressure gas into the gas-liquid mixing section, a liquid-introducing section introducing a high-pressure liquid into the gas-liquid mixing section and an acceleration tube section having a passage from the gas-liquid mixing section to the spraying outlet within the tube section and imparting a momentum to the liquid mist within the passage to form a liquid mist flow. A spiral protrusion extending spirally in the longitudinal direction of the passage is formed on the inside wall of the passage within the acceleration tube.