An endoscope apparatus includes an imaging section that includes a phase difference detection element for implementing phase detection autofocus, and acquires a captured image, a phase difference calculation section that calculates a phase difference based on a signal output from the phase difference detection element, a lens position selection section that selects a lens position that is either a near point-side lens position or a far point-side lens position based on the phase difference, the near point-side lens position and the far point-side lens position being discrete lens positions set in advance, and a driver section that changes a lens position of the imaging section to the lens position selected by the lens position selection section.