In a projection-type display apparatus that projects images onto a screen through a projection lens, even when images, such as setting images of the projection-type-apparatus main unit, that do not need to be displayed on the screen are projected to display, it is also necessary to turn on an expensive light-source lamp whose lifetime is relatively short, resulting in the lifetime of the light-source being shortened. In response to this problem, a lens cover 4 having a display function such as a liquid crystal is therefore used as the lens cover for protecting a projection lens 3, and images that do not need to be displayed onto the screen are displayed on the lens cover 4 having the display function; consequently, light emission from the light-source-lamp is made unnecessary at that time.