Provided is an operation limiting device which makes it possible to achieve more robust security and safety in processing of a workpiece by a processing apparatus. The operation limiting device limits operations relating to processing of a workpiece by a processing apparatus, and is provided with: an authentication unit for authenticating each of a plurality of users; a receiving unit for receiving an operation request or permission for said operation, from a plurality of authenticated users; an operation enabling unit for enabling an operation if an operation request or permission has been received from the plurality of authenticated users; and a releasing unit for releasing the operation enabled state set by the operation enabling unit if processing relating to the operation has terminated or if a predetermined period of time corresponding to the operation has elapsed.