A method for manufacturing a package, includes preparing a lead frame that, in a region where the package is to be formed, has a first electrode and a second electrode that is different from the first electrode; clamping the first electrode and the second electrode between an upper molding die and a lower molding die; injecting a first resin into the molding dies between which the first electrode and the second electrode have been clamped, through an injection opening formed adjacent to the first electrode and on the outside of the region where the package is to be formed; curing or solidifying the injected first resin; and cutting out an injection mark of the injection opening for the first resin from next to the first electrode after the first resin has been cured or solidified.