A light-emitting part (1, 41) for a vehicle and comprising a light-emitting region (10a, 50a), comprising: an irradiation body (20, 60) which comprises a dot-shaped light source (21, 61) and a plane plate-shaped light guide body (22, 62) with a light-emitting surface (22a, 62a) emitting light from the light source (21, 61) and emits the light toward the front side of the light-emitting region (10a, 50a); and a curved plate-shaped transmissive body (10, 50) which is provided at the front position of the irradiation body (20, 60) so that the light emitted from the irradiation body (20, 60) is transmitted through the curved plate-shaped transmissive body (10, 50) as the light-emitting region (10a, 50a), wherein the light source (21, 61) is attached to a position adjacent to an end of the light guide body (22, 62) in a longitudinal direction, wherein the transmissive body (10, 50) comprises portions which are separated from the light guide body (22, 62) at different gaps, wherein the light-emitting part (1, 41) for the vehicle further comprises a surface brightness adjusting portion which adjusts a brightness of an outer surface of the light-emitting region (10a, 50a) in dependency to a size of a gap of the different gaps and a distance from the light source (21, 61) in the longitudinal direction, wherein the surface brightness adjusting portion comprises a reflected light adjusting portion provided in the light guide body (22, 62), wherein the reflected light adjusting portion is provided by a plurality of reflection portions being notches reflecting at least a part of the light incident from the light source (21, 61) toward the light-emitting surface (22a, 62a), characterized in that the depth of the notch forming each of the reflection portions changes depending on the size of the gap and the distance from the dot-shaped light source (21, 61) to adjust the brightness of the outer surface so as to obtain an uniform brightness of the entire outer surface of the light-emitting region (10a, 50a) by suppressing unevenness in brightness of the light-emitting region (10a, 50a) caused by the different gaps, and wherein the depth of the notch is set to be in the range of equal to or larger than 0.075 mm and equal to or smaller than 0.3mm. an irradiation body (20, 60) which comprises a dot-shaped light source (21, 61) and a plane plate-shaped light guide body (22, 62) with a light-emitting surface (22a, 62a) emitting light from the light source (21, 61) and emits the light toward the front side of the light-emitting region (10a, 50a); and a curved plate-shaped transmissive body (10, 50) which is provided at the front position of the irradiation body (20, 60) so that the light emitted from the irradiation body (20, 60) is transmitted through the curved plate-shaped transmissive body (10, 50) as the light-emitting region (10a, 50a), wherein the light source (21, 61) is attached to a position adjacent to an end of the light guide body (22, 62) in a longitudinal direction, wherein the transmissive body (10, 50) comprises portions which are separated from the light guide body (22, 62) at different gaps, wherein the light-emitting part (1, 41) for the vehicle further comprises a surface brightness adjusting portion which adjusts a brightness of an outer surface of the light-emitting region (10a, 50a) in dependency to a size of a gap of the different gaps and a distance from the light source (21, 61) in the longitudinal direction, wherein the surface brightness adjusting portion comprises a reflected light adjusting portion provided in the light guide body (22, 62), wherein the reflected light adjusting portion is provided by a plurality of reflection portions being notches reflecting at least a part of the light incident from the light source (21, 61) toward the light-emitting surface (22a, 62a), characterized in that the depth of the notch forming each of the reflection portions changes depending on the size of the gap and the distance from the dot-shaped light source (21, 61) to adjust the brightness of the outer surface so as to obtain an uniform brightness of the entire outer surface of the light-emitting region (10a, 50a) by suppressing unevenness in brightness of the light-emitting region (10a, 50a) caused by the different gaps, and wherein the depth of the notch is set to be in the range of equal to or larger than 0.075 mm and equal to or smaller than 0.3mm.