To provide a method for manufacturing a plurality of types of illuminating devices having different specifications while reducing cost. A substrate includes a common flexible portion and a plurality of units bendable with respect to the common portion, where the common portion includes a pad that is extended in the horizontal direction in the plane of the drawing and that is arranged for every predefined interval. In the present manufacturing method, a substrate piece is created by cutting the substrate mounted with the light emitting element in a first direction, the common portion in the substrate piece is formed according to the illuminating device to be manufactured, the relative position of the individual portion with respect to the formed common portion is respectively positioned, and the wiring for supplying power to the pad in the substrate piece is formed.