1. An apparatus for data analysis comprising; a processor and a display unit, wherein the processor obtains first roughness parameters indicating characteristics of roughness of edges of a line pattern from cross section data cut in a plane parallel with a substrate based on results obtained by observing a line pattern on the substrate by a scanning probe microscope; displays a first graph using values of the first roughness parameters as one value and values indicating a distance from the substrate of the plane as another value on the display unit; obtains second roughness parameters of the edges of the line pattern extracted according to image processing conditions from an observation image of the line pattern from an upper surface of the substrate by a scanning electron microscope and displays a second graph using values of the second roughness parameters as one value and values indicating the image processing conditions as another value on the display unit, and wherein the processor obtains the image processing conditions for extracting the edge points of the line pattern in the values indicating the distance from the observation image of the scanning electron microscope by obtaining the image processing conditions where the values of the second roughness parameters are equal to the values of the first roughness parameters.