A fluid ejection gun includes: a flexible ejection tube for ejecting a fluid, the fluid being supplied to the inside of the ejection tube, the fluid being ejected from the tip of the ejection tube; a guide disposed to surround the ejection tube and introduce the ejection tube along the inner surface of the guide, the ejection tube being moved by the fluid ejected from the tip ; a casing disposed to surround the guide, the casing having an opening section forward in the ejection direction of the fluid ejected from the tip of the ejection tube; and a suction unit provided to the casing for sucking the fluid ejected from the ejection tube.