To prevent point illumination and fix a light-guiding body. The present invention includes: a fixation portion having a first holding portion and a second holding portion; engagement portions that restrict frontward movement of the one end portion in the front-back direction; an elastic portion that generates elastic force upward in the up-down direction, and abuts on the one end portion to maintain engagement of the engagement portions; contact portions that bring the first holding portion and the one end portion into contact with each other on both sides in the left-right direction; an abutment portion that abuts on the one end portion to restrict backward movement of the one end portion in the front-back direction; and a restriction portion that abuts on the elastic portion to restrict downward movement of the elastic portion in the up-down direction.