PURPOSE: To prevent the porous storing body of a cold trap for purifying molten metal or other use from being clogged locally near the inflow holes by storing packings in the storing body while leaving a space and placing members for supporting the packings in the space.

CONSTITUTION: Packings 11A are stored in porous storing body 13A while leaving space 14. Many inflow holes 12A are made in body 13A by plastic working, and support members 15 corresponding to holes 12A are bent to the packing 11A side to support packings 11A. When sodium or the like contg. impurities flow into holes 12A from the outside of body 13A, the passages are narrowed, and then the flows are diffused in space 14 and enter the whole region of packings 11A. By this mechanism local clogging near holes 12A is prevented to elongate the life of this cold trap.