A semiconductor device includes a semiconductor package, a circuit board and an interval maintaining member. The semiconductor package has a body and a lead protruded from the body. The circuit board has a first land electrically connected to the lead. The interval maintaining member is interposed between the circuit board and the body. The interval maintaining member maintains an interval between the lead and the first land. Thus, an interval between the lead and the land is uniformly maintained, so that a thermal and/or mechanical reliability of the semiconductor device is improved.