the invention is polycarbonate str1 the absorbance distribution of the recording film in the decolored state and that in the colored state shown in fig2 are an absorbance distribution of the diarylethene derivative represented by the above formula i in the case of a ring opening structure and that in the case of a ring closure structure respectively as shown in the above formula this compound normally has the ring opening structure decolored state however the compound has the ring closure structure and is colored colored state when irradiated with a recording light e g ultraviolet rays the compound can return to the decolored state from the colored state by irradiation with visible light erasing light in other words the compound is reversible accordingly in the recording film 3 a change of color from decolored state to colored state or a change of color from colored state to decolored state takes place by the irradiation of the recording film 3 with a light having a specific wavelength polycarbonate used as the binder is a polymer having as a main chain a carbonate bond namely a carbonic acid ester bond o c u2550 o o an example of the polycarbonate is aromatic polycarbonate obtained from sodium salt of bisphenol a and phosgene the aforementioned acid anhydride of diarylethene derivative is contained in the recording film in an amount of 1 to 100 parts by weight.