A steering device includes left and right arm mechanisms each including a front arm and a rear arm whose one ends are rotatably connected to a wheel-mounting portion at wheel-side connecting points and whose other ends are rotatably connected at body-side connecting points. The front arm and rear arm of the arm mechanisms each include a plurality of links, and adjacent links are rotatably connected to each other at an intermediate connecting point. An arm driving device drives the arm mechanisms independently from each other such that the angles of individual links around the connecting points are uniquely determined.