A recording film 3 of phase change type of Sb--Te--Ge system or Sb--Te--In system has at least one of lanthanoid elements and elements selected from among Ag, Ba, Co, Cr, Ni, Pt, Si, Sr, Au, Cd, Cu, Li, Mo, Mn, Zn, Al, Fe, Pb, Na, Cs, Ga, Pd, Bi, Sn, Ti, and V added thereto. A high melting point component 3b is precipitated in the recording film 3 to coexist with a phase change component 3a, thereby preventing the recording film 3 from flowing and segregating during recording and erasing. The recording film 3 can be made not as recording film, but as superresolution readout thin film to mask an optical disc recorded by ruggedness, an optical disc of phase change type, and a magneto-optical disc, thereby increasing number of possible superresolution readouts to a great extent.