A laser processing apparatus (1) according to an embodiment includes a processing chamber (18) configured to perform laser processing for an object to be processed (40), a stage (10) disposed inside the processing chamber (18), the stage being configured to convey the object to be processed (40), and a control unit (50) configured to instruct a loading/unloading apparatus (30) about a placement position of the object to be processed (40) over the stage (10), the loading/unloading apparatus (30) being configured to load/unload the object to be processed (40) into/from the processing chamber (18). Further, the processing chamber (18) includes a loading gate (17a) for loading and an unloading gate (17b) for unloading for the object to be processed (40), and the object to be processed (40) is conveyed only in a first direction from the loading gate (17a) toward the unloading gate (17b) over the stage (10).