To provide an optical film together having excellent heat resistance and optical characteristics so as to form various functional layers at a high temperature.

This optical film contains a polyimide having a repeating unit expressed by general formula (1) [X is a 4-30C divalent group which contains a monocyclic or condensed polycyclic aromatic group or a monocyclic or condensed polycyclic aliphatic group; R1 is a substituent; and n is an integer of 0 to 6] and further having a glass transition temperature of ≥ 340°C.