A spread illuminating apparatus is provided which includes: a light conductor plate having a light inlet surface and two major surfaces; a light source unit disposed at the light inlet surface of the light conductor plate; and a light diffuser pattern disposed at the lower major surfaces of the two major surfaces of the light conductor plate, wherein the light source unit includes first and second white light sources which have respective different light emitting principles, are arranged in the width direction of the light conductor plate with their respective ends set close to one another, and which can be turned on and off independently of each other.