A curved conveyor in a horizontal curved path section of a conveying path has an inner idler wheel array arranged to the inside of the horizontal curved path section with respect to an arc-shaped center line that passes through the center of the path width of the horizontal curved path section, and an outer driving wheel array arranged to the outside of the horizontal curved path section with respect to the arc-shaped center line, wherein the distance from the arc-shaped center line to the outer driving wheel array is smaller than the distance from the arc-shaped center line to the inner idler wheel array.