PURPOSE: To eliminate a short-circuit of adjacent bumps even if a pitch of a bump array is narrowed by forming triangular prismlike bumps alternately having reverse directivities, and arranging the bumps in two rows of a zigzag state.

CONSTITUTION: A polyimide opening 6 of an equilateral triangular shape in which vertexes are alternately arranged upward and downward as seen from a dicing line is patterned at a polyimide precursor to form a wiring protective film 7. Then, an entire wafer 1 is coated with a barrier metal 8, entirely coated with photosensitive resist 9, and the resist 9 is so patterned that a resist opening 10' of an equilateral triangular shape is superposed on a polyimide opening 6' of am equilateral triangular shape on an electrode 4 at the side of vertexes. Thereafter, with the metal 8 as a plating electrode a bump 11' is formed in the opening 10'. Thus, a large distance between the bumps is obtained for a pitch of the electrodes.