PURPOSE: To prevent the sticking of a CO2 snow to snow horns by forming spiral flows of CO2 discharged from nozzles, which rotate in the mutually opposite direction in the snow horn, and joining with each other in the vicinity of the intersection to cancel the spiral flows.

CONSTITUTION: Liquid CO2 is ejected from the nozzles 34, 36 in a continuous expansion chamber having the Y-shaped cylindrical snow horns 4, 6, which have mutually crossed axes 14, 16, 18 in the longitudinal direction, and a discharge duct 8 so as to form the spiral flows of CO2 mutually oppositely rotating along the wall of the snow horns. As a result, the formed CO2 snow falls down to the discharge duct 8 with the kinetic energy of the spiral flows cancelled at the intersection of the aces 14, 16.