In a resin sealing type semiconductor device, a semiconductor chip CP2 is mounted over a die pad DP having conductivity via a bonding member BD2 having insulation property, and a semiconductor chip CP1 is mounted over the die pad DP via a bonding member BD1 having conductivity. A first length of a portion, in a first side formed by an intersection of a first side surface and a second side surface of the semiconductor chip CP2, covered with the bonding member BD2 is larger than a second length of a portion, in a second side formed by an intersection of a third side surface and a fourth side surface of the semiconductor chip CP1, covered with the bonding member BD1.