An endoscope 2 includes: a CCD 11 that picks up an image of a subject an FPGA 13 that is controlled by a main body portion 3 to output a drive signal for driving the CCD 11 and transmits an image pickup signal outputted from the CCD 11 to the main body portion 3 rewritable flash memory 14 in which at least one of program data and setting data that relate to an operation of the FPGA 13 is stored and a switch group 15 that, based on a rewriting instruction signal SW to the data in the flash memory, switches so that the data received by using all or a part of signal lines for the CCD 11, the lines being associated with observation of the subject, is inputted to the flash memory 14.