A method for manufacturing a package includes the steps of: preparing a lead frame having a frame, a first electrode, a second electrode, a first connecting portion connecting the frame and the first electrode, and a second connecting portion connecting the frame and the second electrode; placing the lead frame in a mold; injecting a first resin into the mold from an inlet of the mold located adjacent to the first electrode to mold a flange portion and a wall portion of the package; and cutting the lead frame and a part of the flange portion located adjacent to the first electrode. In the step of injecting the first resin, the mold and the lead frame together provide a hollow space into which the first resin is injected and in which a part of the flange portion is formed so as to have a thickness different from a thickness of the lead frame.