A method for manufacturing a package includes molding a precursor of a package including a cup-shaped resin component having a bottom surface and side walls, an opening opened at an upper part of the side walls, and a pair of leads exposed on the bottom surface. The side walls include a side wall that extends along the Y axis and the X axis and that has a first outer surface, and a side wall that extends along the Y axis and the Z axis. A thickness of the side wall extending along Y axis and the X axis is less than a thickness of the side wall extending along axis and the Z axis. The first outer surface has a recess which is recessed in the Z axis direction and arranged in a position corresponding to the opening. The method further includes forming a reflective film in the recess.