A semiconductor package including an internal package including at least one semiconductor chip sealed with an internal seal, an external substrate on which the internal package is mounted, and an external seal sealing the internal package is provided. Also provided is a method of manufacturing the semiconductor package including forming an internal package including at least one semiconductor chip sealed with an internal seal, mounting the internal package on an external substrate, and sealing the internal package with an external seal. The internal seal and the external seal have different Young's moduli, for example, a Young's modulus of the internal seal is smaller than a Young's modulus of the external seal. Accordingly, the semiconductor package is less susceptible to warpage and can be handled with relative ease in subsequent semiconductor package processes.