A processing method for transferring a job to execute an image process from a first image processing device to a second image processing device replacing the first image processing device as a subject of an agreement, the first image processing device including: a first memory; a first connector to which an external memory is connectable; a first controller; and a first communication interface, the second image processing device including: a second connector to which the external memory is connectable; and a second controller, the processing method comprising: the first controller receiving a function deactivation instruction to deactivate a prescribed function of the first image processing device (S112, S11); after the first controller receiving the function deactivation instruction, the first controller acquiring a piece of identification information for the second image processing device from an external device via the first communication interface (S112, S12); the first controller storing, in the external memory connected to the first connector, the acquired piece of identification information and job information which is stored in the first memory, the job information specifying a job to perform an image process (S114, S24); subsequently to connection of the external memory to the second connector, the second controller determining whether the piece of identification information stored in the external memory matches a piece of identification information for the second image processing device; and when the piece of identification information stored in the external memory has been determined to match the piece of identification information for the second image processing device, the second controller executing the image process according to the job information stored in the external memory with the subject of the agreement changed to the second image processing device. the first controller receiving a function deactivation instruction to deactivate a prescribed function of the first image processing device (S112, S11); after the first controller receiving the function deactivation instruction, the first controller acquiring a piece of identification information for the second image processing device from an external device via the first communication interface (S112, S12); the first controller storing, in the external memory connected to the first connector, the acquired piece of identification information and job information which is stored in the first memory, the job information specifying a job to perform an image process (S114, S24); subsequently to connection of the external memory to the second connector, the second controller determining whether the piece of identification information stored in the external memory matches a piece of identification information for the second image processing device; and when the piece of identification information stored in the external memory has been determined to match the piece of identification information for the second image processing device, the second controller executing the image process according to the job information stored in the external memory with the subject of the agreement changed to the second image processing device.