Abstract: A carbon dioxide snow ejecting device is provided to achieve efficient cleaning by widely ejecting carbon dioxide snow while suppressing consumption loss of carbon dioxide gas. The device includes a carbon dioxide gas supply source for generating carbon dioxide snow, a straightened-flow gas supply source for supplying straightened-flow gas for propelling the carbon dioxide snow, a carbon dioxide snow ejection port 1, and first straightened-flow gas discharge ports 3 incliningly opposing to each other so that the carbon dioxide snow ejection port 1 is located therebetween. The device forms the ejected carbon dioxide snow in a flat shape by the effects of the straightened-flow gas. Thus, unlike conventional techniques, neither loss nor generation of particles will not be caused by the carbon dioxide snow collides the internal surface of a nozzle. Therefore, it is able to prevent situations where loss of carbon dioxide gas and poor cleaning.