A sample observation device includes: an emission optical system that emits planar light to a sample; a scanning unit that scans the sample in one direction so as to pass through an emission surface of the planar light; an imaging optical system that has an observation axis inclined with respect to the emission surface and forms an image of observation light generated in the sample by emission of the planar light; an image acquisition unit that acquires image data corresponding to an optical image of the observation light formed by the imaging optical system; and an image generation unit that generates observation image data of the sample based on the image data acquired by the image acquisition unit. The imaging optical system has a non-axisymmetric optical element that bends a light beam on one axis of the observation light but does not bend a light beam on the other axis perpendicular to the one axis.