A thin projection type image display device with a low chin height includes a cabinet, a screen, a projection optical system, an optical path changing unit, and a reflecting unit. The screen is disposed on a front side of the cabinet. The projection optical system enlarges and projects an image formed by a display element, and the optical path changing unit is disposed on the bottom of the cabinet to reflect the image enlarged and projected by the projection optical system. The reflection unit is disposed obliquely to the screen and below the screen to reflect the image reflected by the optical path changing unit toward the screen. The projection optical system is disposed in a space above a horizontal plane perpendicular to the screen, behind the front side of the cabinet, and below an optical path of light incident on a bottom of the screen.