Imaging device and control method

A function relating to communication of imaging data is assigned to an operational switch of an operating unit. A control unit switches a working mode of the assigned assignment function among a stop mode in which power supply to a communication unit that communicates the imaging data is stopped, a standby mode in which standby is performed to enable the communication of the imaging data by supplying power to the communication unit, and an executing mode in which the imaging data is communicated, depending on operational duration of the operational switch. In a case where the imaging data is not communicated, the assignment function is set to the stop mode, thereby realizing power saving. Further, the working mode of the assignment function can be switched depending on the operational duration of the operational switch, which improves the operability of an imaging device.