A semiconductor package is provided with a package body including a base part and a semiconductor device housing part housing a semiconductor device. An electric terminal electrically connected to the device is provided in the housing part and is exposed to an outer surface. A high heat transfer element is arranged from a heat generating part corresponding position corresponding to a heat generating part of the device to a position outside the corresponding position in the base part. The base part is configured by contacting a plurality of thin sheets mutually closely with each other and by bonding integrally with each other. The high heat transfer element includes particles configured by a material having a thermal conductivity higher than that of the base part and dispersed in the base part. The particles are dispersed between two mutually adjacent thin sheets among the thin sheets.