MIRROR DEVICE

A mirror device includes: a mirror having a rotation shaft and a reflecting surface that reflects display light; a support portion having a cylindrical shape, having a base end fixed and a tip end being a free end, and configured to rotatably support the rotation shaft; and a motor that pivots the mirror, in which the rotation shaft is inserted into the support portion while spreading the support portion outward in a radial direction, and is slidably supported by the support portion.