A light apparatus mounted on a vehicle includes a lamp unit having: a first cover, and a light source that emits light through a first cover into a predetermined area including a first direction. The light apparatus also includes: a radar unit provided on a lower side or an upper side of the lamp unit, and a separator provided between the lamp unit and the radar unit. The radar unit includes: a circuit board having a board surface arranged in a substantially horizontal state, and an antenna unit that transmits an electromagnetic wave in a range including a second direction different from the first direction and that receives a reflected wave from an object existing outside the vehicle. The antenna unit is arranged in the board surface.