A semiconductor device includes a tape carrier substrate having a flexible insulating film base, a plurality of conductor wirings provided on the film base, and wiring bumps respectively formed so as to cover an upper surface and both side surfaces of the conductor wirings, and a semiconductor chip mounted on the tape carrier substrate, wherein electrodes of the semiconductor chip are connected to the conductor wirings via the wiring bumps. Electrode bumps are formed on the electrodes of the semiconductor chip, the electrodes of the semiconductor chip are connected to the conductor wirings via a bonding between the wiring bumps and the electrode bumps, and the electrode bumps are harder than the wiring bumps. This structure can reduce bonding damages to the electrodes of the semiconductor chip caused by a process of connecting the electrodes and the conductor wirings via the bumps.