A semiconductor package encapsulating a semiconductor chip provides inner leads and outer leads for establishing electrical connections with the substrate. Herein, a lead frame is set into the metal mold, into which a resin is injected and which is clamped in proximity to the outer leads. Thus, the semiconductor package is sealed so as to avoid unwanted formation of resin burrs around lower surfaces of the inner leads. In addition, a semiconductor device is produced using a package in which a semiconductor chip mounted on a stage and terminals are embedded within a resin. Each terminal provides an electrode surface, an interconnecting portion, and an exposed terminal surface. Herein, an isolation portion is formed as an integral part of the package made by the resin and is arranged in the prescribed area between the electrode surface and the exposed terminal surface.