A head up display unit having such a structure that a user can be imaged regardless of opening/closing of a combiner member. Visible light (L) emitted from a display means (2) is reflected by the combiner member (concave mirror)(4) provided operably toward the user (D) thus forming a display image (V). The head up display unit comprises a means (5) for irradiating infrared rays toward the user (D), means (6, 7) for imaging the face of the user (D) by receiving the infrared rays reflected off the user (D) through the combiner member (4) when it is open and receiving the infrared rays reflected off the user (D) not through the combiner member (4) when it is closed, and an image processing means (8) for calculating the positions of the eyes of the user (D) based on an image picked up by the imaging means (6, 7).
