A thin film transistor substrate and a method for manufacturing the same are discussed, in which the thin film transistor comprises a gate line and a data line arranged on a substrate to cross each other; a gate electrode connected with the gate line below the gate line; an active layer formed on the gate electrode; an etch stopper formed on the active layer; an ohmic contact layer formed on the etch stopper; source and drain electrodes formed on the ohmic contact layer; and a pixel electrode connected with the drain electrode. It is possible to prevent a crack from occurring in the gate insulating film during irradiation of the laser and prevent resistance of the gate electrode from being increased.