To provide a light reflector winch can prevent a light intensity reflecting film made of silver from being discolored even if it is used adjacent to a light source generating heat and ultraviolet rays by using thermoplastic resin composition little generating corrosive gas in a base material and has excellent heat resistance and light resistance, and an illuminator using the light reflector.

In the light reflector where the high intensity light reflecting film 3 made of silver or silver alloy is formed on a surface opposite to the light source 7, the base material 2 positioned at least above the position where the light source 7 is installed is formed of thermoplastic norbornane resin composition or thermotropic liquid crystal resin composition.