A display apparatus that displays a virtual image having a shape that follows an object to be superimposed when viewed from a user is provided. An optical system that is included in the display apparatus and displays a virtual image that is three-dimensional includes a laser that emits laser light, a MEMS scanner that performs scanning with the laser light, a screen that forms an image on a surface of the screen with the MEMS scanner scanning the surface with the laser light, a projection unit that generates a virtual image by projecting the image formed onto a display medium, and a drive unit that reciprocates the screen scanned with the laser light in a predetermined section along an optical path of the optical system at a predetermined cycle. The MEMS scanner changes a vertical movement speed of a scan line according to a shape of an object included in a background and is superimposed with the virtual image in scanning performed with the laser light at a scanning cycle in synchronization with a cycle of the reciprocation.