A method of measuring a pattern by using a display microscope image comprises a step of setting an edge detection reference line by designating a range of detecting an edge and a number of edge points with regard to a respective side portion of the pattern in the microscope image, a step of sampling the edge point constituting a point of changing a brightness from image information by searching the edge point from a direction orthogonal to the set edge detection reference line, a step of providing a line approximating the respective side portion of the pattern based on position information of a plurality of the edge points and a step of specifying a shape of the pattern by an intersecting point of two pieces of lines, a specified point provided by a plurality of intersecting points, an angle made by two pieces of straight lines and a distance between two specified points from information of the approximated line approximating the respective side portion of the pattern.