A semiconductor device is reduced in size. The semiconductor device includes a die pad, a plurality of leads arranged around the die pad, a memory chip and a power source IC chip mounted over the die pad, a logic chip mounted over the memory chip, a plurality of down bonding wires for connecting the semiconductor chip to the die pad, a plurality of lead wires for connecting the semiconductor chip to leads, and a plurality of inter-chip wires. Further, the logic chip is arranged at the central part of the die pad in a plan view, and the power source IC chip is arranged in a corner part region of the die pad in the plan view. This reduces the size of the QFN.