To construct a three-dimensional image having the original tint of a sample.

In the case of constructing the stereoscopic image of a sample due to a volume rendering method on the basis of image data acquired by respectively photographing each slice 1 obtained by continuously slicing the sample to be an observation object thinly, a slice picture reflecting the transmissivity of the slice and a slice picture reflecting reflectance are obtained about the slice by performing image pickup due to lighting by rear face illumination 6 lighting the slice from a rear side and front illumination lighting 4 and 5 lighting the face of the imaged side of the slice respectively, the data of the picture (picture by rear face illumination lighting) reflecting the reflectance is used as the voxel value of a corresponding voxel in each voxel constituting the stereoscopic image to be constructed, and the data of the slice picture (picture by front illumination lighting) reflecting the transmissitivity is replaced with opacity being a parameter that decides how much the color information of each voxel should be reflected and is reflected as the opacity of the corresponding voxel in the stereoscopic image.