PURPOSE: To facilitate management, maintenance and visual observation to work by supplying salt crystallized grains from upstream side in shifting course to make porous platelike salt formed body, pouring molten metal and dissolving and removing the salt formed body after cooling and solidifying.

CONSTITUTION: The crystallized grains 8 continuously supplied on the shift forming course 7 from a supplying part 9 are formed to the fixed thickness of porous platelike salt formed body 10 after passing through clearance at between a nip roll 3 and upper face of the course 7 and preheated at preheating part 12. Successively, the salt formed body 10 is shifted to a molten metal supplying part 15 and a thickness control part 16. The molten metal 17 is supplied from a molten metal crucible 13 and pressed into voids among the grains 8 in the salt formed body 10, infiltrated and filled up. Successively, the molten metal is cooled and solidified with injection spraying member 18 in a cooling-solidifying part 19 for molten metal 17. Further, the salt formed body 10 is dissolved with injection shower from shower spray 20 and housed in a water vessel 22 and a continuative void type foam metal formed material 25 with mutually communicated network metal fiber 17b can be produced as continuous long platelike.