To provide a lens for an illuminating device able to set more appropriately the light distribution angle of the illuminating device according to the purpose of the use of the illuminating device and also able to set more appropriately the brightness of a part which is irradiated with illumination light.

In a lens 5 for the illuminating device formed in a flat plate, its one side 5a has a Fresnel lens face 5b formed from a Fresnel lens, and its other side 5c has a fly-eye lens face 5d formed from a fly-eye lens, and a convex lens face 5e formed from a single convex lens.