To provide a device for drilling a long element capable of drilling the long element securely even in the event that a sensor provided on a stopper malfunctions.

The device for drilling the long element cuts a hole in the long element W by setting in a predetermined position the long element W conveyed by a conveyor 1. The device includes a stopper 2 provided in such a manner as to retractably move onto the path A of conveyance of the conveyor 1 so as to abut against the end of the long element W and set the long element W in the predetermined position; a first sensor 24 provided on the stopper 2 for detecting that the long element W abuts against the stopper 2; a transverse clamp 4 for clamping from both right and left sides the long element W abutting against the stopper 2; a second sensor 43 for detecting the presence of the long element W via a through hole 42 formed in the transverse clamp 4; and a drill 5 for cutting a hole in the long element W. If both the first sensor 24 and the second sensor 43 detect the long element W, drilling is performed therein by the drill 5.