The present invention provides an inspection apparatus and inspection method. The wavelength of the incident radiation is outside the detectable range. Furthermore, an accessory device, such as a headset, is also associated with the main device and co-located with a relevant object. In order for the operator to more efficiently utilize the printing system to perform a large number of print jobs with as few interruptions as possible, the present invention provides a user friendly navigational tool, which can provide the operator with information regarding the amount of printing supplies currently available in the printing system. Thus, it is possible to stably store highly integrated information. Thus, it is possible to miniaturize a transistor and to extend an effective channel length of the transistor.