The present invention provides a light-field microscope including: an illumination optical system that radiates excitation light onto a sample; and a detection optical system including an objective lens that collects fluorescence generated in the sample as a result of the sample being irradiated with the excitation light by the illumination optical system, an image-acquisition element that acquires an image of the fluorescence collected by the objective lens, and a microlens array disposed between the image-acquisition element and the objective lens. The illumination optical system radiates a beam of the excitation light having a predetermined width in the optical-axis direction of the objective lens so as to include the focal plane of the objective lens onto the sample in a direction substantially perpendicular to the optical axis.