An optical glass containing Si, Al, Ca, and O is provided. The optical
glass contains Si in an amount of 7% or more and 93% or less, in cation
percent, Al in an amount of 2% or more and 57% or less, in cation
percent, and Ca in an amount of 2% or more and 52% or less, in cation
percent. In the optical glass, a total amount of Si, Al, and Ca is 99.5%
or more, in cation percent. Further, the optical glass contains Fe and Na
each in an amount of 0.01 wtppm or less and has a transmittance to a
light having a wavelength of 248 nm of 15% or more at a thickness of 5
mm.