PURPOSE: To prevent contaminations of floor and the like due to drop of water during transportation and scattering of deposits and transport altogether by extracting a filter medium as a frozen black and thawing to through after transporting to other place.

CONSTITUTION: Refrigerant is flown out of a freezer 7 around a jacket cylinder 6 provided inside of filter body 1 and the layers of spent filters medium 2 charged in the cylinder 6 is frozen together with dirt and the like left in the layers to be a block together with a hanging metal hook. After freezing, hot water is flown out of a heating device to around the cylinder for heating and thawing only the part of ice sticking on the cylinder 6 and filter medium layers 2 to make it easy to hang out the filter medium layers 2. The filter medium layers 2 hung out is put on filter medium layer support rods 13 provided in a filter medium thawing and throwing device. The filter medium layers 2 are thawed gradually here and the filters medium separated into pieces fall on a filter medium distributor plate, through between the support rods 13, along a guide stripe 15 and into a drum can 16. By this, the contamination of floor and the like due to the drop of water included in the filter medium and scatter of dirt and the like depositing on the filters medium are prevented.