Prior lead wire forming methods of this type may be divided into two types. According to the first method as shown in FIG. 1, the lead wires of an electric part 1 is pushed by a pushing means 2 in a direction indicated by arrow A, so that they are forced into a pair of lead wire grooves 3a and 3b of the forming means 3 and formed and held therein. According to the second method as shown in FIG. 2, a pushing means 2 moves in a direction indicated by arrow B, so that the lead wires of an electric part are forced into lead wire grooves 3a and 3b in a chucking manner between a lever 4 and the pushing means 2 and formed and held therein. Since such methods, however, are forming methods based on the dimensions of the lead wires, in order to bend the lead wires as shown in FIG. 3, an additional length corresponding to the widths W of the contact portions of the pushing means must be provided in addition to the length L of a body member of an electric parts to reach the overall length of the part, thereby increasing the insertion pitch P on a printed circuit board. Therefore, the space required for each part when it is mounted on a printed circuit board must include the widths W, thereby making the printed circuit board larger and more costly than if such widths could be eliminated. Moreover the lead wires may be damaged by chucking between the pushing means 2 and the forming means 3.