A semiconductor package includes a first chip, a second chip stacked over the first chip and having a different size from the first chip, a first guard unit formed in an edge of a chip having a relatively small size of the first chip and the second chip, and a second guard unit formed in an edge of a chip having a relatively large size of the first chip and the second chip. The first guard unit includes an extension pad which expands the size of the chip having the relatively small size to the size of the chip having the relatively large size.