1. A non-transitory image processing device for making a comparison between an optical microscope image acquired by an optical microscope, and an image acquired by a charged-particle beam device, comprising: a comparing unit which makes a comparison between said optical microscope image of a specimen stained for an observation made by said optical microscope and an elemental mapping image, said optical microscope image being acquired by said optical microscope, said elemental mapping image being based on detection of X-rays by said charged-particle beam device, and a storing unit which selects locations as acquisition locations for a charged-particle beam image by said charged-particle beam device in a descending order of coincidence degrees between said optical microscope image and said elemental mapping image in said specimen, and stores position information of the selected locations.