A
machining center is provided, which can complete replacement of processed works on stock shelves in a work storage section with unprocessed works within a time period significantly shorter than those in conventional techniques and improve the efficiency of an entire
processing process. In the
machining center, a cover surrounding the work storage section includes an opening portion where rear surface regions of the stock shelves are exposed, a stock shelf access door that closes the opening portion and is driven to be opened and closed, a locking device for the stock shelf access door, a unlocking mechanism that is operable from the outer side of the cover to unlock the locking device, and a door opening / closing detection device that detects an opened or
closed state of the stock shelf access door. A
control unit of a CNC device includes an
interlocking function of disabling the unlocking mechanism while an automatic
pallet changer is driven, and a
safety control function of prohibiting, based on a detection
signal from the door opening / closing detection device, a drive unit of the automatic
pallet changer from being driven while the stock shelf access door is in the opened state.