1. A method for inspecting a shape of a tire, comprising the steps of: sampling an image of a tire side surface having a knurled region; Fourier-transforming the image of the tire side surface; removing a Fourier component along the tire circumferential direction and a Fourier component along the tire axial direction in the Fourier-transformed image as those corresponding to the knurled region when the two Fourier components are on a single straight line and at the same time appear in a predetermined shape at predefined intervals on the straight line; obtaining an image of a tire side surface with the knurled region removed by inverse-Fourier-transforming the image from which the Fourier components corresponding to the knurled region have been removed; and determining the acceptability of the shape of the tire by comparing the image with the knurled region removed against a reference image of a tire side surface.