A semiconductor package includes a first redistribution substrate, a first semiconductor chip mounted on the first redistribution substrate, a second semiconductor chip disposed on a top surface of the first semiconductor chip, an insulating layer surrounding the first and second semiconductor chips on the first redistribution substrate, a second redistribution substrate disposed on the second semiconductor chip and on which the second semiconductor chip is mounted, and a connection terminal disposed at a side of the first and second semiconductor chips and connected to the first and second redistribution substrates. An inactive surface of the second semiconductor chip is in contact with an inactive surface of the first semiconductor chip. At an interface of the first and second semiconductor chips, an upper portion of the first semiconductor chip and a lower portion of the second semiconductor chip constitute one body formed of a same material.