Lifespan of LEDs can be lengthened, and the workability of the printed circuit board during circuit formation and during LED mounting can be improved.A metal base circuit board, having an insulating layer with a linear expansion coefficient of 60 ppm per degree C. or higher and 120 ppm per degree C. or lower, a metal foil provided on one side of the insulating layer, comprising a metal material with a linear expansion coefficient of 10 ppm per degree C. or higher and 35 ppm per degree C. or lower, a circuit portion and a non-circuit potion having a linear expansion coefficient of 10 ppm per degree C. or higher and 35 ppm per degree C. or lower, and a white film formed on top of the insulating layer, circuit portion, and non-circuit portion, the total sum of the areas of the non-circuit portion and the circuit portion on top of the insulating layer being 50% or higher and 95% or lower relative to the area of the metal foil, and the relation between the linear expansion coefficients of each of the materials being: linear expansion coefficient of insulating layer>linear expansion coefficient of metal foil>linear expansion coefficient of circuit portion and non-circuit portion.