A stack package usable in a three-dimensional (3D) system-in-package (SIP) includes a first semiconductor chip, a second semiconductor chip, and a supporter. The first semiconductor chip includes a through silicon via (TSV), and the second semiconductor chip is stacked on the first semiconductor chip and is electrically connected to the first semiconductor chip through the TSV of the first semiconductor chip. The supporter is attached onto the first semiconductor chip so as to be spaced apart from an edge of the second semiconductor chip.