A focus driving control unit 34 of a control unit 30 sets a ranging area to a ranging size at the time of a speed priority driving which is a region size set in advance, for example, in a case in which a defocus amount of a ranging area is greater than a ranging area determination threshold set in advance. In a case in which the defocus amount is equal to or less than the ranging area determination threshold, the focus driving control unit 34 sets the ranging area to a subject priority ranging size which is a region size different form the ranging size at the time of the speed priority driving. For example, in a case in which an imaging mode is a mode in which a moving subject is imaged or a case in which a subject is a moving subject, the subject priority ranging size is set to be greater than the ranging size at the time of the speed priority driving. In a case in which the imaging mode is a mode in which a stationary subject is imaged or a case in which a subject is detected to be a stationary subject, the subject priority ranging size is set to the ranging size at the time of the speed priority driving or to be less than the ranging size at the time of the speed priority driving. Therefore, it is possible to easily perform stable focus control.