An image pickup system is an image pickup system in which an image pickup device arranged at a distal end of an insertion section of an endoscope and a processor can communicate with each other. A group of multiple control parameters to be collectively transmitted and checksum codes related to the parameters are transmitted from the processor to the image pickup device, and the image pickup device reflects the control parameters on a register only when all the received multiple control parameters are normal, on the basis of the checksums.
