A LOC type semiconductor device comprises a semiconductor chip having a main surface in which semiconductor elements and a plurality of bonding pads are formed, and a back surface opposite the main surface; a plurality of leads each having an inner part and an outer part, and including a plurality of first leads having inner end portions extended on the main surface of the semiconductor chip and a plurality of second leads having inner end portions terminating near the semiconductor chip; bonding wires electrically connecting the bonding pads to bonding portions of the inner parts of the first and the second leads; and a sealing member sealing the semiconductor chip therein. A first bending portion is formed in the inner part of each second lead to prevent the sealing member from transformation by forming the sealing member in satisfactory resin balance between an upper portion and a lower portion of the sealing member.