A reflow apparatus includes a reflow furnace. A transfer device holds and transfers printed circuit boards with to-be-reflowed electronic components thereon from an inlet to an outlet of the furnace within the furnace. A plurality of adjusting/circulating sections separate an ambient gas for heating the printed circuit boards into predetermined temperature regions in the furnace in which the ambient gas is circulated in a heated state. A feed port is formed in the furnace to feed the ambient gas into the furnace under pressure. Residence parts each provided between adjacent adjusting/circulating sections regulate the amount of the ambient gas when the ambient gas, after having been sent to and heated in the adjusting/circulating section adjacent to the feed port, is circulated and sequentially moved to the adjusting/circulating sections at the inlet or the outlet and finally flows out through the inlet or outlet into atmosphere. Suction ports are open to the furnace to suck the ambient gas from the inside of the furnace. A flux removing unit is separate from the furnace and removes components of a flux from the ambient gas sucked through the suction ports from the inside of the furnace.
