PURPOSE: To suppress the damage to be given on an optical tape medium by heating the optical tape medium to a temp. below its m. p. and transferring the guide patterns corresponding to the shape of guide grooves to a recording layer while subjecting the medium with photoirradiation.

CONSTITUTION: The optical tape medium 4 is set 'on a heating roller 1 and feed rollers 2, 3 by providing a prescribed angle of inclination. While the medium 4 is fed at a prescribed feed speed, the part wound around the roller 1 is irradiated with the light of a prescribed wavelength at this time. The roller 1 is heated to the prescribed temp. below the m. p. of the medium 4 at this time. The optical recording layer 42 contg. the diaryl ethene material of the medium 4 in contact with the projecting part of a mold 11 of the guide tracks formed on the roller 1 is heated simultaneously with the photoirradiation, by which a ring closing reaction is largely progressed. However, the layer 42 of the parts to the recessed parts is not so much heated and the degree of progression of the ring closing reaction is lowered. The guide track patterns are easily formed without pressurization to the medium 4 and the damage is suppressed.