A light source unit includes light sources and a light source substrate. Each of the light sources includes terminals. The light source substrate includes a support layer, a wiring portion, mounting portions, an insulating cover layer, locking edges, and solder portions. The support layer has flexibility and an insulating property. The wiring portion is formed on the support layer. Each of the mounting portions includes lands provided midway in the wiring portion and facing each other at a distance. The mounting portions are assigned to the light sources, respectively. The insulating cover layer is formed on the support layer to cover the wiring portion and includes opening edges. The locking edges are formed by sections of the opening edges to overlap the lands in a non-linear manner in a plan view. The solder portions conform and adhere to the locking edges and electrically connect the lands to the terminals.