A reflow system in which a reflow furnace is sequentially divided into a plurality of zones along a conveying path of a heat target which is conveyed and by controlling temperatures of the plurality of zones, the heat target which is conveyed is reflowed has: a cooling and flux collecting apparatus circulating and cooling atmosphere gases in furnace bodies of a part or all of the plurality of zones and collecting a flux; and a flow rate control unit which is inserted into a circulating path of the atmosphere gas of each of the zones and can control a flow rate. When the temperature of the zone is reduced, by controlling the flow rate control unit, the flow rate is set to be higher than that upon collecting the flux.