An image obtaining apparatus includes: a light source configured to irradiate a biological sample having a fluorescent label with an excitation light, the excitation light exciting the fluorescent label; a focus moving unit configured to move a focus position of an optical system in the thickness direction of the biological sample; and a data processing unit configured to expose an image sensor to light while moving the focus position of the optical system in each of a plurality of preset scanning ranges to thereby obtain fluorescent images of the biological sample, each of the plurality of scanning ranges having a predetermined scanning length, the predetermined scanning length being smaller than the length of a bright-point detection range of the biological sample in the thickness direction, the center positions of the scanning ranges being different from each other in the thickness direction.