To reduce the time necessary for the installation work and construct safe handrails and join baseboards linearly.

A holding cylinder 3 for a post and a holding plate 4 for a baseboard are erected with an appropriate distance on base plate 2 and a baseboard-retaining part 6 is formed with the holding cylinder 3 and the holding plate 4. A fastening bolt 5b is fitted to a fastening plate 5a and a fixing member 5 that a nut 5c is screwed on the fastening bolt 5b is arranged at the lower part of the base plate 2 to constitute a handrail post.fitting metal 1 for the baseboard. The handrail post.fitting metal 1 for the baseboard is fitted in a hanging hole while holding the upper face plate of a lining plate with the base plate 2 and the fastening plate 5a, and the handrail post 15 is fixed in the holding cylinder 3 and the baseboard is held at the baseboard-retaining part 6. A baseboard-connecting fitting 20 that baseboard-connection plates 22, 23 to hold the ends of the baseboard continuously arranged on a flat plate 21 are parallelly erected, is arranged between two handrail posts.fitting metals 1 for the baseboard on the lining plate W.