To provide a linear lighting device using a long transparent material which enables easy fixture to an attachment member, prevents assembly error, and obtains a high quality lighting pattern.

A linear lighting device includes: a long transparent material; a light source provided at an end part in a longitudinal direction of the transparent material; and a case which houses the transparent material and the light source. A stepped cutout is provided at the other end part of the transparent material which is opposite to the end part. A protruding part, which protrudes into the cutout and is disposed in the cutout, is provided on a case inner surface facing the cutout.