PURPOSE: To efficiently use the space on a step section recessed from a floor and enlarge the effective area of the floor, by providing a lid at the same height as the surface of the floor over the step so that the lid can be opened and closed and be attached and detached.

CONSTITUTION: When a van with its cab over the engine is used for a physically handicapped person on a wheelchair, a lid 47 is removably attached to a step section 84 provided at the floor 43 of the rear room of the vehicle and located at an entrance, which is opened or closed by a slide door. The lid 47 can be opened and closed. Hinges 85a, 85b are removably attached to the edges of the floor 43 and the corresponding ones of the lid 47. The opposed edges of the floor 43 are fitted with bearers 86 for supporting the lid 47. The lid 47 placed on the bearers 86 is secured by engaging slide stoppers 87a with members 87b. Grippers 88 and a wheel stopper 44c are mounted on the top of the lid 47.