The present disclosure enables lighting performance which appears as if there are more light sources than the actual number of light sources, and reduces brightness unevenness. A vehicular light-emitting device includes a plurality of light-emitting units, each of which includes an LED part and a lens configured to diffuse and emit the light received from the LED part, the plurality of light-emitting units being arranged side by side. The plurality of light-emitting units are arranged so that one or more brightness peak values exist between adjacent light-emitting units. Moreover, the light emitted from the lenses of the light-emitting units has a plurality of brightness peaks with respect to the spreading direction of the light, and the arrangement interval of the plurality of light-emitting units is set so that the plurality of brightness peaks of the light emitted from the plurality of light-emitting units are aligned at substantially equal intervals.