A semiconductor device having a molded sealing resin for sealing a semiconductor chip on a circuit board thereof reduces resin burrs resulting from the leakage of the sealing resin, and also restrains the occurrence of disconnection caused by a wiring layer being crushed. In the semiconductor device, the sealing resin for sealing the semiconductor chip is molded on the circuit board that has a plurality of wiring patterns and a solder resist for insulatively covering the wiring patterns formed on the front surface thereof, the interval of the wiring patterns is set to range from 50% to 200% of its adjacent interval in a molding line area of the sealing resin.