Provided is an image-acquisition apparatus that includes: a stage on which a specimen is mounted; an objective lens that collects light from the specimen mounted on the stage; a motor that drives the stage in the direction intersecting an optical axis of the objective lens; an imaging device that acquires images by capturing the light collected by the objective lens; and a processor comprising hardware, wherein the processor is configured to implement: a deterioration-level calculation unit configured to calculate deterioration levels contained in the acquired images; and an image generating unit configured to generate a pasted image by pasting the acquired images, wherein the image generating unit is configured to generate the pasted image by combining, for a common region of two images that are mutually pasted, an image with lower deterioration level calculated by the deterioration-level calculation unit at a higher combining ratio.