Head-up display

A head-up display including a display panel, a non-mechanical focusing lens, and a determining unit is provided. The display panel is configured to emit an image beam. The non-mechanical focusing lens is disposed on a transmission path of the image beam and generates an image of the image beam. The determining unit is electrically connected to the non-mechanical focusing lens and configured to adjust a focal length of the non-mechanical focusing lens according to a sensing signal, so as to change an image distance from the image to a user's eye.