The present invention achieves a light guide unit capable of, with use of minimum-sized reflection means, (i) preventing light from directly leaking out from a light guide through a surface of the light guide and thus preventing luminance unevenness, and also (ii) suppressing an increase in production costs. Specifically, reflection means (8) is provided on an upper surface of a light guide part (2a) so as to cause light entered a light guide (2) to travel toward inside of the light guide (2). The reflection means (8) extends from one intersection (P) of first intersections so as to cover a region, of the upper surface of the light guide part (2a), which faces a light incidence surface (9) right above a light source (6). Each of the first intersections is an intersection of (i) a straight line extending at an angle θ to a vertical line (M) and passing through a second intersection and (ii) the upper surface of the light guide part (2a). The one intersection (P) of the first intersections is furthermost from the light source (6) among the first intersections. The vertical line (M) extends from an edge, of the light source (6), which is closest to the light emitting surface (2c) toward the light incidence surface (9). The second intersection is an intersection at which the light incidence surface (9) and the vertical line (M) intersect.