According to one embodiment, a recording medium records a shape calculation program that causes a computer to calculate a shape of a periodic structure. The shape calculation program causes the computer to extract a second scattering profile from a first scattering profile obtained when the electromagnetic waves are incident and to extract a fourth scattering profile from a third scattering profile calculated using a second periodic structure that is virtually set. The shape calculation program causes the computer to perform fitting between the second scattering profile and the fourth scattering profile and to calculate the shape of the first periodic structure on the basis of the result of the fitting.