An illumination device, comprising: a light emitting panel; and a device body to which the light emitting panel is detachably attached, characterized in that the light emitting panel has an electroluminescence element, wherein the light emitting panel has a rear surface facing the device body and serving as a first curved surface, the device body having a surface facing the light emitting panel and serving as a second curved surface conforming to the first curved surface, an attachment portion configured to attach/detach the light emitting panel to/from the device body to slide in a sliding direction along the first curved surface or the second curved surface is provided on one of the rear surface of the light emitting panel facing the device body and the surface of the device body facing the light emitting panel, and a groove portion, configured such that the attachment portion slides on the groove portion, is provided on the other of the rear surface of the light emitting panel facing the device body and the surface of the device body facing the light emitting panel, and wherein a ridge is provided on one of the first curved surface of the light emitting panel and the second curved surface of the device body, a valley for engaging with the ridge when the light emitting panel is attached to the device body being provided on the other of the first curved surface of the light emitting panel and the second curved surface of the device body, wherein the light emitting panel has cutout portions formed in end portions of the light emitting panel in the sliding direction thereof, the cutout portions being configured to prevent the light emitting panel from interfering with an adjoining illumination device when removing the light emitting panel of the adjacently positioned illumination device from a device body of the adjacently positioned illumination device. a light emitting panel; and a device body to which the light emitting panel is detachably attached, characterized in that the light emitting panel has an electroluminescence element, wherein the light emitting panel has a rear surface facing the device body and serving as a first curved surface, the device body having a surface facing the light emitting panel and serving as a second curved surface conforming to the first curved surface, an attachment portion configured to attach/detach the light emitting panel to/from the device body to slide in a sliding direction along the first curved surface or the second curved surface is provided on one of the rear surface of the light emitting panel facing the device body and the surface of the device body facing the light emitting panel, and a groove portion, configured such that the attachment portion slides on the groove portion, is provided on the other of the rear surface of the light emitting panel facing the device body and the surface of the device body facing the light emitting panel, and wherein a ridge is provided on one of the first curved surface of the light emitting panel and the second curved surface of the device body, a valley for engaging with the ridge when the light emitting panel is attached to the device body being provided on the other of the first curved surface of the light emitting panel and the second curved surface of the device body, wherein the light emitting panel has cutout portions formed in end portions of the light emitting panel in the sliding direction thereof, the cutout portions being configured to prevent the light emitting panel from interfering with an adjoining illumination device when removing the light emitting panel of the adjacently positioned illumination device from a device body of the adjacently positioned illumination device.