PROBLEM TO BE SOLVED: To provide an imaging device and an imaging system which can perform stable signal transmission.SOLUTION: An imaging device includes: an imaging part for outputting an electric signal after photoelectric conversion from a plurality of pixels as image information a transmission part for outputting the image information outputted by the imaging part outside a synchronous signal generation part for generating a synchronous signal having a prescribed cycle a reception part for receiving the synchronous signal transmitted from outside a mode switching part for switching a slave mode in which the transmission part transmits the image information on the basis of the synchronous signal received by the reception part and a master mode in which the transmission part transmits the image information on the basis of the synchronous signal generated by the synchronous signal generation part and a transmission control unit which controls transmission operation of the transmission part on the basis of a standby signal that is received by the reception part from outside and sets transmission of the image information by the transmission part to either a transmission state or a stop state.
