To enable operation to hold a bent part on a plane simply while the bent part and its periphery of a hollow panel are being made a surface without a projected installation part.

A holding part 1, the base parts 4 of rods in which support parts 2 are installed serially through an elbow part 3 in one base part 4 in which a connection part is installed is attached to a joint part 5. Structure in which the rods are installed slidably between ribs of a hollow panel 13 is made, and an article is constituted in which the panel 13, an opening part 15 in which the joint part 5 can move, a bent part 17 and a notch are formed in a place in which the elbow part 3 is positioned at a time of free bending.