Patent ID: 8159749

Claim:
An antireflection coating formed on a transparent substrate, comprising: an Al film having a transmittance of lower than 10% at a wavelength of 550 nm with a thickness of 25 nm, the Al film predominantly composed of aluminum (Al); and an Al—N film formed in at least one of an upper layer and a lower layer of the Al film and having a transmittance of equal to or higher than 10% at a wavelength of 550 nm when measured at a thickness of 25 nm, the Al—N film predominantly composed of Al and comprising a nitrogen (N) element as an additive, wherein a specific resistance of the antireflection coating is equal to or lower than 1.0×10 −2 Ω·cm, and a reflectance of a surface of the Al—N film is equal to or lower than 50% in a visible light region.