The reflector coated with high reflectivity gold film can be used in the wide spectrum of near infrared and infrared spectrum. In order to enhance the adhesion of gold film, a very thin chromium base film is coated. The gold film on silicon substrate has strong adhesion and high thermal conductivity, and its heat resistance is much better than that on glass substrate. Because it is a gold film, the reflectivity or reflectivity wavelength characteristics will not change greatly with the incident angle. In the infrared spectrum region, it has high reflectivity, and the light without reflection is completely absorbed by the film and will not pass through.