To easily fix a roof carrier bar to a different height by constituting the roof carrier bar of a base interposed between a body and a roof of a vehicle and a bolt for fixing the body to the roof of the vehicle via this base, and manufacting the base by cutting a preformed slender member.

This roof carrier bar installing device has a rubber blindfold cover 14 for covering an outside surface of a base 12 in a skirt shape, and is threadedly engaged with an installing part 2 by a bolt 15 by respectively penetrating through a bolt penetrating hole 11 of a flange 10, a through hole of the cover 14 and a bolt penetrating hole 13 of the base 12, and is composed of a key cover 16 for covering the upper side of a bolt 15 part and the upper side of the blindfold cover 14, a locking device 17 arranged in this key cover 16 and a key groove 18 formed on an upper outside surface of the base 12 for holding this locking device in a locking position by engaging with a locking piece of this locking device 17. The base 12 is manufactured sufficiently high by extrusion molding, and is used by cutting the lower part so as to become a height corresponding to a roof shape of a vehicle.