An imaging device that is activated quickly and prevents deterioration of an image signal. The imaging device includes a boosting circuit for boosting an input voltage to generate a boosted voltage. A solid state imaging device receives the boosted voltage and generates the image signal. A clock signal generation unit is connected to the boosting circuit to determine a timing for generating the image signal in correspondence with a vertical synchronization signal and a horizontal synchronization signal and to generate a boosting clock signal for operating the boosting circuit. The clock signal generation unit continuously generates the boosting clock signal during a predetermined period in which the imaging operation starts and, after the predetermined period, generates the boosting clock signal during at least part of a blanking period of the vertical synchronization signal and the horizontal synchronization signal.