An imaging device includes an imaging lens which obtains an optical image of a subject, an imaging element which receives from a subject light passing through the imaging lens, a focus position determination unit which determines a focus position of the imaging lens according to image data obtained from the imaging element and a lens movement unit which moves the imaging lens, the focus position determination unit including an AF operation start position determination unit configured to calculate an AF evaluation value according to the image data, and determine an AF operation start position according to the AF evaluation value when the lens movement unit drives the imaging lens to a predetermined operation start position.