The sample imaging apparatus includes: a housing that forms a closed space; a transparent tray on which a sample is placed in the housing; a plane light source that is formed by using a flat light guide plate, which propagates light emitted by a light emitting element in a plane direction, so as to illuminates the sample with illumination light through the tray in the housing; a lens that is disposed in the housing so as to face the plane light source with the tray interposed between the lens and the plane light source and is used for imaging the sample; and an imaging control unit that adjusts a focal length of the lens and performs imaging in a case of imaging the single sample.