PURPOSE: To improve the safety in a clearance part and to prevent an invasion of foreign matters by providing an engaging member to engage with a recessed groove projecting to a skirt guard side, and an inner deck piece of a synthetic resin furnishing a projection to a footboard side along the inclining angle of a inner brake inclination.

CONSTITUTION: An inner deck 4 furnishes an inclination 4A higher at a handrail panel 3 side and lower at a footboard 1 side, a projection 4B projecting to the footboard 1 side more than a skirt guard 5 and blocking a clearance S, and a wide recessed groove 4C in the form projecting to the guard 5 side, opening sideway facing the footboard 1 side, and making the guard 5 side wider than the opening width. Furthermore, an inner deck piece 7 made of a synthetic resin is installed to the recessed groove 4C. And in the deck piece 7, its hard engaging member 7A is installed to the recessed groove 4C from the end in the longitudinal direction of the deck 4, and a soft projection 7B which is unitary with the engaging member 7A is projected to the footboard 1 side along the inclining angle of the inclination 4A of the deck 4. And the deck piece 7 is cut in the length same as the length of the deck 4, and its joint Q is cut obliquely to expose no sharp angle.