A COF board includes an insulating layer, and a terminal portion formed on the insulating layer. The terminal portion includes a first lead extending in a longitudinal direction, and a second lead extending in the longitudinal direction, and having a smaller length in the longitudinal direction than a length of the first lead in the longitudinal direction. The first leads are arranged in spaced-apart relation in a direction perpendicular to the longitudinal direction. The second leads are arranged in the direction perpendicular to the longitudinal direction to be interposed between the mutually adjacent first leads such that, when the mutually adjacent first leads are projected in an adjacent direction thereof, overlap portions where the second leads overlap with the first leads and non-overlap portions where the second leads do not overlap with the first leads are formed. Dummy leads are provided at the non-overlap portions.