Abstract: A hot gunning robot system moves a gunning nozzle along a vertical center line of the furnace and changes the swiveling angle of the gunning nozzle to perform mending of all interior side and bottom surfaces of the furnace. The system comprises a shifter transferring the nozzle carrier from a housing position to a mending position in the furnace. The shifter has parallelogram-links and an actuator which actuates the links to move the nozzle carrier in an upright constant orientation. A water feeding tube is fitted on a vertical feeding pipe to mix lining material powder with water to obtain a sludgy lining material introduced into the gunning nozzle smoothly by guide vanes provided in a cylindrical nozzle supporter. The nozzle carrier is partitioned into a driving chamber and an air chamber and both of chambers are air cooled. A driving system and bearing system for the vertical feeding pipe is protected from the heat of the furnace.