A pattern measuring method and a pattern measuring apparatus that efficiently prevent a measurement error inherent to a device that performs beam scanning in a specific direction such as a scanning electron microscope are provided. The invention is directed to a pattern measuring method and a pattern measuring apparatus in which a first curve with respect to an edge of one side and a second curve with respect to an edge of the other side are obtained by calculating a first power spectral density with respect to the edge of one side of a pattern and a second power spectral density with respect to the edge of the other side of the pattern based upon a signal that is obtained when a charged particle beam is scanned in a direction intersecting the edge of the pattern; a difference value between the first curve and the second curve is calculated; and one of the first curve and the second curve is corrected by using the difference value.