PURPOSE: To obtain an economical forming jig, which allows repeated usage, by a method wherein shape memory alloy is used for the stock of the forming jig.

CONSTITUTION: Both ends in longitudinal direction of a plate, to which shape memory characteristics are given, are connected to each other so as to form a ring. The ring is restricted to a starlike form at normal temperature and, after that, heat-treated so as to memorize the starlike form. The stock con cerned has characteristics, which restore its memorized shape at about 50°C. Under the state that the jig is not used, the jig is deformed in the state as indicated in the figure (a) so as to save space for storage. Next, the jig is deformed so as to take the central space as wide as indicated in the figure (b) in order to obtain the central space, into which material to be formed is easily poured, and, after that, placed on a heated metal plate and finally choco late liquid, which is heated up to about 80°C, is poured in the central space. At this time, the forming jig, which surrounds the poured chocolate liquid, is heated by the heat of the material to be formed up to 50°C or above and restores the memorized starlike form.