A method of measuring a pattern shape of performing a shape measurement of a semiconductor pattern at a high accuracy even when a process margin is narrow with respect to miniaturization of a semiconductor device is provided. In the method of measuring a pattern shape, when a best-match calculated waveform cannot be selected, at least one parameter among shape parameters is set as a fixed value based on information obtained by another measurement apparatus that uses a measurement method independent to the pattern shape measurement, a matching of a library and a detected waveform is performed again, a best-match calculated waveform is selected, and shape information of an object pattern is obtained from the best-match calculated waveform.