A laser beam passage (10) arranged outside a robot unit of a multi-articulated arm type industrial laser robot has a base (71), a swivel body (72), a first robot arm (74) supported for swing motion, a second robot arm (76) pivotally joined to the first robot arm (74), and a robot wrist (80) attached to an front end of the second robot arm (76) and provided with a laser beam emitting head (79) to connect a laser oscillator (12) to a laser beam receiving unit (77) provided on a rear end of the second robot arm (76). The laser beam passage means (10) has a first laser beam shifting system (20) routing a laser beam emitted by the laser oscillator (12) to an extremity thereof, and having a plurality of rotary joints (R.sub.1, R.sub.2), one telescopic linear-motion joint (S.sub.1), a plurality of laser beam conduits (24, 26) and built-in laser beam reflecting mirrors (25, 27); and a second laser beam shifting system (30) routing the laser beam from the extremity of the first laser beam shifting system (20) toward the laser beam receiving unit (77) attached to the rear end of the second robot arm (76), and having a plurality of rotary joints (R.sub.4 to R.sub.6), a plurality of laser beam conduits (32, 35, 37) and built-in laser beam reflecting mirrors (34, 36).