PURPOSE: To make it possible to certainly load a spring on a specified position by providing a pilot body for a spring loading guide of which end jaw is inserted into a portion of one side of the opening section of the end edge of a thin slab shaped case.

CONSTITUTION: A pilot body 61 has a moving guide path 62 for a spring 17 and also has a jaw 63 capable of being inserted into the opening section 14 of the end edge of a slab shaped case 11. The pilot body 61 performs reciprocation between a position at which the jaw 63 is separated from the opening section of the end edge and a position at which the jaw 63 is inserted into the opening section of the end edge. A pusher rod 81 can enter the opening section 14 of the end edge of the slab shaped case 11 passing through the central path 33 of a spring transfer block body 31 and the moving guide path 62 of the pilot body 61. An elastic body 100 is brought into contact with an end of the spring 17 projected outside from the opening section 14 of the end edge of the slab shaped case 11 to push the spring inside.