The present invention is a combination of a lower plate that are provided in the upper and lower fan in the discharge holes of the radially formed in the top plate and the center which relates to a diffuser for by annealing which is uniform and improved production is easy and durability discharge of the air, the wire bundle loading It includes a top plate body and the discharge hole unit formed in the top plate main body, wherein the discharge hole unit is made alone, a plurality of units to be formed are dispersed in the top plate main body to form a plurality of holes in groups of holes of jidoe group and the hole group the top plate is radially disposed about the center of the upper plate body; And a lower plate body and a lower radial plate which is provided on an upper surface of the lower plate body, the lower radial plate lower plate made of a plurality of unit lower radial plate which is radially disposed about the center of the lower plate body; includes, the plate is the upper plate and the lower plate portion of the unit down when the lower coupling characterized in that the radius of which is disposed between the hole groups form a side wall of the flow path unit.