We have developed efficient spectrally selective infrared (IR) emitters that can be utilized for thermophotovoltaic (TPV) power generation by using stainless steel (SUS304) substrates coated with β- FeSi 2 thin films. To develop spectrally selective emitters, we theoretically propose antireflection (AR) coatings consisting of a single layer of a dielectric material having a high refractive index (∼5) and are appropriate for use with metals such as stainless steels in the IR region. This type of AR coating is fabricated by sputtering a β- FeSi 2 thin film on a polished SUS304 substrate. The reflectance in the IR region is successfully reduced to less than 10%. In addition, the AR properties are stable even at 700 K in air. Therefore, metals with AR coatings of β- FeSi 2 can be applied to IR emitters in TPV systems.