Three stacks composed of high refractive index substance layers and low refractive index substance layers, which are alternately arranged, are formed on one side of a substrate. Of the three stacks, the central stack has a number of layers which are about half the number of all the layers and each individual layer is set so as to be a desired optical quarter-wave thickness. Two stacks are arranged on opposite sides of said central stack, which stacks each have a number of layers of about 1/4 times the number of all the layers and which are set so as to be different in optical thickness from each other and different from the desired quarter wave optical thickness of the central stack layers, said stack combination being capable of easily producing a multi-layer interference filter having good spectrometic characteristics.