To prevent temperature interference between conveying paths in a reflow device having a plurality of conveying paths.

A reflow furnace 2 includes a first carrying conveyer 3 and a second carrying conveyer 4 carrying a substrate W in a conveying path 9 to form a first conveying path and a second conveying path. The first carrying conveyer 3 and second carrying conveyer 4 are respectively composed of inner conveyers 31, 41 arranged to be positioned on an inner side in an orthogonal direction to a conveying direction in the reflow furnace 2, and outer conveyers 32, 42 arranged in approximately parallel to the inner conveyer 31. The inner conveyer 31 includes an aluminum guide rail 31a horizontally arranged in approximately parallel to the conveying direction to pass from a receiving port 7 through the conveying path 9 to a discharge port 8. A shielding body 5 preventing the temperature interference between the first conveying path and second conveying path is arranged on the guide rail 31a.