PURPOSE: A sunlight sensor for a vehicle is provided to exactly measure the location of the sun and exactly compensate insolation by increasing a difference value between the output values of a left direction detection sensor part and a right direction detection sensor part. CONSTITUTION: The sunlight sensor(100) for a vehicle comprises the followings. A body(110) is made of an optical permeable material and is transmitted by sunlight. A left direction detection sensor part(113) is arranged in one side of the concentrate light area of the body. The left direction detection sensor part generates a sensing signal(119a) which corresponds to the quantity of sunlight. A right direction detection sensor part(115) is arranged in the other side of the concentrate light area of the body. The right direction detection sensor part generates a sensing signal(121a) which corresponds to the quantity of the sunlight. A center transverse part(1111) is horizontally formed along the upward center of a lens part. The partition wall(1112) is formed to be extended in the lower portion of the center transverse part.
