Provided is a combiner unit which suppresses a change before and after a rotation of a combiner in the way of showing an image overlapped with an outside view. The combiner unit includes a combiner (210) which is used for a head-up display (1) and reflects a light beam emitted from a light source (10) toward a user to project an image drawn by the light beam in a field of view of the user; and an angle adjusting mechanism (220) which holds the combiner (210) to be rotatable about a virtual axis (210b) traversing an almost center in a vertical direction of the combiner (210) that is erected with respect to a horizontal plane, and which adjusts an inclined angle of the combiner (210) with respect to a vertical plane by rotating the combiner (210) about the virtual axis(210b).
