PURPOSE: To separate the engaging sections of both leg bodies confronted with each other according to the operation of an operating lever, from engaging recessed sections respectively, easily, and exactly by setting the operating lever for separating the engaging sections from the engaging recessed sections, between members for supporting the engaging sections, and members for forming the engaging recessed sections.

CONSTITUTION: In the folding device of leg bodies 3 for forming engaging recessed sections 13 for engaging the leg bodies 3 in a risen state, on bearing brackets 2 for supporting the leg bodies 3 to be freely risen and fallen, fitting engaging sections 8a supported on the upper flange sections 6 of the leg bodies 3, into the engaging recessed sections 13 with the energizing force of energizing members 16, and keeping the leg bodies 3 stably in the risen state, the engaging sections 8a, 8a of the leg bodies 3, 3 confronted with each other are formed with one movable bar 8, and both the engaging sections 8a, 8a are integrally connected with an operating section 8b, and an operating lever 17 for retaining the operating section 8b is set, and by operating the operating lever 17 rotationally, the movable bar 8 is driven in a specified lever ratio, and both the engaging sections 8a, 8a are respectively separated from the respective engaging recessed sections 13, 13, and the engaged state of the leg bodies 3, 3 confronted with each other is released easily at the same time.