Walking-beam type heating furnace

A walking-beam type heating furnace comprising fixed beams which retain workpieces fed into the heating furnace and are laid in a furnace length direction, and walking beams which sequentially transfer said workpieces on the fixed beams from an inlet area to an outlet area and are laid in the furnace length direction, wherein for said walking beams to transfer elongate workpieces placed in a direction crossing a transfer direction, concaves to retain said elongate workpieces are formed at least on said walking beams, and wherein the concaves on the walking beams in the inlet area for heating the workpieces fed into the heating furnace have a flat horizontal bottom surface with two vertical sides and are increased in width in the transfer direction to ensure that a workpiece curved in the transfer direction crossing the longitudinal direction thereof is out of contact with a workpiece retained in the adjoining concave, while the concaves on the walking beams in the outlet area allowing the heated workpieces to be wholly heated to a uniform temperature and retained in position are formed in a corrugated configuration.