The present invention is to provide an air heating device having a position-controlled fence member capable of improving heat collection performance by reducing the difference in temperature distribution inside the heat collecting space through which air flows and increasing heat transfer efficiency with the air flowing inside the heat collecting space. . The present invention for this purpose is provided with an air flow channel, at least a portion of the duct body exposed to an external heat source; A blower for providing a conveying pressure of air passing through the air flow path; A heat transfer plate disposed on the air flow path, in contact with the air passing through the air flow path, and heated by heat transferred from the external heat source; A first fence assembly disposed to protrude from an upper side from one surface based on a center line of the heat transfer plate; A second fence assembly disposed to protrude from the upper side from the other side surface based on the center line of the heat transfer plate; An assembly connection part rotatably connecting the first fence assembly and the second fence assembly; And a position adjusting unit connected to the assembly connection part and changing the positions of the first fence assembly and the second fence assembly while moving the assembly connection part along the conveying direction of air.