DISPLAY DEVICE, CONTROL METHOD, PROGRAM, AND STORAGE MEDIUM

A head-up display 2 according to the embodiment includes the combiner 5 and the light source unit 6 and displays facility marks indicating facilities existing in front of the vehicle Ve. The combiner 5 displays the facility marks at positions corresponding to the facilities existing in the front scenery of the vehicle Ve. The control unit 55 of the light source unit 6 determines the display states of each facility mark corresponding to the low priority facility Ptag based on the directional change rate dD of the low priority facility Ptag.