This information processing apparatus includes: a search image acquisition unit that acquires enlarged images at focal positions different from each other; a first feature amount calculation unit that obtains, for each of the multiple captured enlarged images, a first feature amount based on a direct current component and a dynamic range of an alternating current component of pixel values for each of blocks forming each of the enlarged images; and an in-focus position determination unit that determines an in-focus position of each enlarged image based on the first feature amount.