A processing speed of each mechanisms in a cutting section is controlled such that all polarizing films housed in a container in advance are used in a joining process and simultaneously a new container with polarizing films housed therein that are cut by a size of a liquid crystal panel is loaded from the cutting section. Here, a fracture included in the polarizing film is cut and removed in the cutting section while a delayed time due to this process is shortened by controlling at least a processing speed in a processing mechanism in a cutting mechanism among mechanisms provided in the cutting section and the joining section.