Inner walls of a reflecting cup of a light emitting device include a base plane, a first pair of parallel planes, and a second pair of planes. The first pair of parallel planes are perpendicular to the base plane. The second pair of parallel planes are perpendicular to the base plane, and cross the first pair of parallel planes at right angles. An LED chip which emits a blue light is provided on the base plane. The LED chip is sealed in the cup by a fluorescent member including a fluorescent material, for example YAG. A ratio of a length of the first pair of parallel planes along a plane perpendicular to the optical axis of the light emitted from the LED chip and a length of the second pair of parallel planes along the perpendicular plane equals the aspect ratio of a photographing area of a camera which is used with the light emitting device.