Abstract: A projection-type video display apparatus comprising: a transmission-type screen; a video projection unit configured to project an image displayed on a video display surface as an image light; a projection optic system configured to enlarge and project the image light projected from said video projection unit on a rear surface of said transmission-type screen; and a plane mirror, provided in a part of said projection optic system, configured to reflect the image light from said video projection unit, thereby to project it on said transmission-type screen, wherein said transmission-type screen, said video projection unit and said projection optic system are mounted on a base; said video projection unit builds up an oblique projection optic system; and said transmission-type screen and said plane mirror are disposed on said base, being perpendicularly fixed, independently, in parallel with each other, and on the rear surface of said transmission-type screen is attached a foldable back cover, detachably, so as t