Abstract: The present invention relates to a folding container having a bottom portion 100 having locking blocks 108, 109, 113 formed thereon and on which the bottom portion of a folded folding container can be fitted, and side walls having recesses 210, 307 formed therein and each having an open underside into which the corresponding locking block of an assembled folding container can be inserted, wherein engagement frame sections 207, 308 are used to mutually engage the side walls and to engage the side walls with the bottom portion. Therefore, folded folding containers can be stably stacked up, and the folding container can be strongly assembled in the form of a box because the engagement frame sections are used to mutually engage the side walls and to engage the side walls with the bottom portion.