1. A computation model generating device, comprising: a processor specifically configured to function as: an image reading unit that reads a plurality of images in which a plurality of cells incubated in an incubation container are image-captured in time series; a feature value calculating unit that obtains from the plurality of images, for each of the plurality of cells included therein, feature values of a plurality of different kinds representing morphological features of the cell; a frequency distribution calculating unit that obtains, from each of the plurality of images, frequency distributions by obtaining a frequency distribution for each of the plurality of different kinds of the feature values, the frequency distribution calculating unit normalizing a frequency division in each of the frequency distributions; and an evaluation information generating unit that (i) obtains variations of the frequency distributions over a lapse of time from combinations of the frequency distributions that are for the same kind of the feature values and that are from images of the plurality of images having different photographing time points, (ii) selects at least one combination from a group of the combinations of the frequency distributions, the combinations constituting the group differing in at least one of photographing time points of the images and kinds of the feature values, and (iii) obtains a computation model of evaluation information that evaluates an incubated state of the plurality of cells based on a variation of the frequency distributions in the at least one selected combination.