A light-emitting device (20) includes a light-emitting region (140). The light-emitting region (140) includes a plurality of light-emitting units (142) and a plurality of light-transmitting units (144), and each of the plurality of light-transmitting units (144) is located between the light-emitting elements (142) adjacent to each other. The light-emitting region (140) is located on a side of one surface (outer surface (202)) of a base material (200) having light-transmitting properties and has an inclination with respect to the one surface (outer surface (202)). The base material (200) is rear glass of an automobile. The base material (200) partitions a region outside a mobile object (region (RG1)) from a region inside the mobile object (region (RG2)).