1. A pattern measurement device comprising: a computation device using a waveform signal obtained by scanning a pattern with a charged particle beam to measure a measurement target pattern, wherein the computation device classifies pattern sites which are repeatedly arrayed at a specific interval, based on phase information on an array of an edge of the pattern having a specific period, on the basis of the waveform signal, and executes a pattern edge type identification, a pattern type identification, or measurement of dimensions between predetermined pattern sites, on the basis of association between the classified pattern site, and information pertaining to a pattern edge type, or information pertaining to a pattern type.