To provide an optical unit capable of restricting the incorporation of a flexible substrate and the bending of the substrate toward both sides in an outer surface direction in the minimum space.

The optical unit includes an optical adjusting member 102 and a holding part E for holding the flexible substrate 29. The holding part includes first projecting parts 917a and 917b and second projecting parts 918a and 918b which are separately arranged on one side and the other side in a first direction along the substrate surface of the flexible substrate, also, on both sides in the thickness direction of the flexible substrate, and also, arranged in different positions in the second direction orthogonal to the first direction along the substrate surface. The arrangement order of the first and second projecting parts on one side in the second direction is different from that on the other side.