A method of manufacturing a semiconductor package which includes mounting a first chip on a first substrate by a flip chip method, the first substrate having a pre-designed pattern formed thereon; forming a cavity by etching a center portion of a metal oxide layer; mounting a second chip inside the cavity; forming at least one via such that the via penetrates an edge of the metal oxide layer; placing the metal oxide layer on the first substrate such that the second chip and the first chip face each other; and placing a second substrate on the metal oxide layer, the second substrate having a third chip mounted thereon.