One aspect of the present disclosure provides a laser line generator that includes a laser beam source, a conversion lens, a lens holder, a rotation axis, a rotation support, a biasing portion, and a gap adjuster. The rotation support abuts the rotation axis and supports the lens holder such that the lens holder rotates about the rotation axis. The biasing portion brings the lens holder and the rotation support closer to each other. The gap adjuster adjusts a gap dimension between the lens holder and the rotation support that are brought closer to each other by the biasing portion.