To improve workability and flexibly use a connection member at a step.

This connection member comprises a first elbow member 6 of approximately a U-shape in cross section and bent in the direction of an opening, and a second elbow member 5 formed into a U-shape in cross section and coupled with the first elbow member and bent in the direction of an opening or in the direction of a back reverse to the opening. One elbow member 5 is provided at one end part with nipping parts 51a and 52a to nip the side wall of one wire gutter for a wiring and at the other end with engaging part 51b which is engaged with the elbow member 6. The other elbow member is provided at one end part with nipping parts 61a and 62a to nip the sidewall of the other wire gutter for a wiring and at the other end part with parts 61b and 62b which are to be engaged to longitudinal displaceably engage the engaging part of one elbow member.