PURPOSE: To enable the sublimable substance to be recovered easily to the outside of the apparatus, by sending the sublimable gas under pressure into the collector with the jet pump while ejecting a gas of low temperature as the driving fluid from the nozzle and solidifying the sublimable gas to the form of powdery snow.

CONSTITUTION: The sublimable gas is sent in being passed through the valve 10, the gas of low temperature passes through the valve 17 from the pipe 16, is ejected with high speed from the nozzle 19 and is mixed with the sublimable gas. The mixed gas is sent into the collector 1 under pressure through the diffuser 20. The sublimable gas is cooled, is solidified to the form of powdery snow and is made to collide against the baffle plate 18 in the apparatus 1. The sublimable substance which has become particles, passes through the valve 14, is recovered from the pipe 13 and the gas of low temperature and the unsolidified sublimable gas pass through the valve 11 and are exhausted from the pipe 12