A semiconductor device, comprising: a semiconductor element mounted on a mounting surface of a lead frame; a first mold resin that seals the mounting surface; a second mold resin that seals a heat dissipating surface of the lead frame opposing the mounting surface, and wherein a thinly-molded portion covering the heat dissipating surface of the lead frame and a lead frame space filled portion disposed in at least one portion of a die pad space between two separate regions of the lead frame are integrally molded from the second mold resin; the lead frame space filled portion being a portion of second mold resin filling the die pad space; wherein the lead frame is covered with a metal plating, characterized in that it has a scale form portion, wherein the scale form portion is such that the metal plating coating the lead frame is formed by spot irradiation melting; wherein the melting causes a surface form of the metal plating to change into a scale form, and the scale form portion is such that scale form projections are continuously disposed and both sides of the scale form projection are raised; wherein the scale form portion is disposed in an outer peripheral portion of either or both of the mounting surface and heat dissipating surface of the lead frame; the semiconductor device further characterized by a depressed portion for improving the adhesion between the first mold resin and the second mold resin owing to an anchor effect that is provided in the first mold resin or the second mold resin at a joint portion of the first mold resin and the second mold resin in the die pad space between the two separate regions of the lead frame. a semiconductor element mounted on a mounting surface of a lead frame; a first mold resin that seals the mounting surface; a second mold resin that seals a heat dissipating surface of the lead frame opposing the mounting surface, and wherein a thinly-molded portion covering the heat dissipating surface of the lead frame and a lead frame space filled portion disposed in at least one portion of a die pad space between two separate regions of the lead frame are integrally molded from the second mold resin; the lead frame space filled portion being a portion of second mold resin filling the die pad space; wherein the lead frame is covered with a metal plating, characterized in that it has a scale form portion, wherein the scale form portion is such that the metal plating coating the lead frame is formed by spot irradiation melting; wherein the melting causes a surface form of the metal plating to change into a scale form, and the scale form portion is such that scale form projections are continuously disposed and both sides of the scale form projection are raised; wherein the scale form portion is disposed in an outer peripheral portion of either or both of the mounting surface and heat dissipating surface of the lead frame; the semiconductor device further characterized by a depressed portion for improving the adhesion between the first mold resin and the second mold resin owing to an anchor effect that is provided in the first mold resin or the second mold resin at a joint portion of the first mold resin and the second mold resin in the die pad space between the two separate regions of the lead frame.