1. A method of constructing a three-dimensional image, comprising the steps of: obtaining a first series of tilted images which are constituted by electron microscope images or elemental mapping images of a sample at different tilt angles and which have been obtained by tilting the sample in a plurality of angular increments; obtaining a second series of tilted images which are constituted by electron microscope images or elemental mapping images of the sample at different tilt angles and which have been obtained by rotating the sample about an axis perpendicular to a surface of the sample when the sample is in the same state as when the first series of tilted images was obtained and then tilting the sample in a plurality of angular increments; and constructing the three-dimensional image on the basis of the first and second series of tilted images.