A cell controller includes an inside information acquiring unit for acquiring the inside information of the plurality of manufacturing machines, and an inside information comparing unit which compares, with regard to a first manufacturing machine and a second manufacturing machine, which are selected by the comparison object selecting unit, first inside information and second inside information, which are acquired, and the inside information comparing unit extracting a difference therebetween. The cell controller also includes an abnormality cause finding unit for finding a cause of an abnormality that occurs in the first manufacturing machine or the second manufacturing machine, based on the difference, and an abnormality cause conveying unit for conveying the cause of the abnormality to the outside of the cell controller.