According to one embodiment, an interference filter includes a base body, a lower semi-transmissive layer, and an upper semi-transmissive layer. The base body includes a major surface. The lower semi-transmissive layer is provided on the major surface. The upper semi-transmissive layer is provided on the lower semi-transmissive layer. The base body, the lower and upper semi-transmissive layers form a first region to selectively transmit blue light, a second region to selectively transmit green light, and a third region to selectively transmit red light, arranged in a plane parallel to the major surface. A distance between the lower semi-transmissive layer and the upper semi-transmissive layer in the second region is shorter than a distance between the lower semi-transmissive layer and the upper semi-transmissive layer in the first region, and shorter than a distance between the lower semi-transmissive layer and the upper semi-transmissive layer in the third region.