The invention provide a vehicle inclined plate capable of suitably assisting an operation by a user. The vehicle inclined plate (1) is provided with more than two plate bodies (10) which are slidablerelative to each other； side rails (20) which are provided at the end portions of the plate bodies (10) in a width direction； and a slide auxiliary mechanism which assists the relative slide between the side rail (20) at one side and the adjacent side rail 20 at the other side. The slide auxiliary mechanism includes a rotating body (30) and a tapered rollers (40A, 40B).
