A semiconductor manufacturing system for performing a predetermined process in accordance with a job file having a process content set therein. The manufacturing system includes a storage device for memorizing a job file, an accepting device for accepting a job file, a correction device for correcting, on the basis of a process content of a job file already memorized, a process content set in a job file as newly accepted, and a predicting device for predicting a time for completion of the process, on the basis of the job file as already memorized and the job file having its process content corrected by the correction device.