The present invention provides a technique to generate an accurate connected image even in a monotonous pattern using design data as constrained conditions. A reference position is roughly determined through matching between the design data and image data, matching between neighboring images is performed using the amount of mismatch from the design data as a searching range and a connected image is generated at high speed and accurately. The image generation method of the present invention is an image generation method for inspecting an electronic device pattern using a scanning electron microscope and is constructed of a design data file that stores design data describing layout information of an electronic device pattern by inputting the data, a plurality of divided pieces of image data obtained by imaging the electronic device pattern at different imaging positions, and image connecting means for connecting the plurality of divided pieces of image data into one image using the plurality of divided pieces of image data and the design data of a file of the design data (see FIG. 1).