A semiconductor device with TSV and its fabrication method are revealed. The semiconductor device primarily comprises a chip and a flexible metal wire inside. A redistributed trace layer and a passivation layer are formed on the active surface of the chip. A through hole penetrates the chip from the active surface to the back surface, in which an insulation layer is disposed. The flexible metal wire has a first terminal and a second terminal where the first terminal is bonded to a redistributed pad of the redistributed trace layer and the second terminal passes through the through hole and protrudes from the back surface of the chip. Therefore, the flexible metal wire passing through the chip has two protruded integral terminals to achieve high stress resistance TSV with lower costs for good electrical connections of vertical stacking chips.