PROBLEM TO BE SOLVED: To provide a 90-degree horizontal rotator which rotates vertical steel plate-made roof materials at 90 degrees in the horizontal direction to change to lateral arrangement so as to dry a large number of steel plate-made roof materials at one time, e.g. in drying steel plate-made roof materials in their production process.SOLUTION: A 90-degree rotation body 74 is attached, freely rotatably in the 90-degree horizontal direction, in a sprocket 73 attached to a frame 70 and being freely rotatable by a drive motor 71, and a rotary conveyor 75 capable of transferring and mounting a steel plate-made roof material 1 is attached to the upper surface 74A of the 90-degree rotation body 74. A steel plate-made roof material 1 mounted vertically (vertical arrangement y) on the rotary conveyor 75 of the 90-degree rotation body 74 can be modified freely in arrangement to the lateral arrangement (x) by rotating the 90-degree rotation body 74 in the 90-degree horizontal direction.
