1. An image pickup device comprising: an image sensor which picks up an image of an object; a selection control unit which selects any one of plural face detection modes set beforehand as an operation mode in detecting a face region; a face detection unit which detects a face region from an object image picked up by the image sensor in accordance with values of a first parameter and a second parameter, the first parameter and the second parameter corresponding to a face detection mode selected by the selection control unit and defining a detection condition for detecting a face region; an operation unit through which a user gives an image-pickup instruction of recording the object image and sets an image-pickup preparation prior to the image pickup instruction; and a mode control unit which always sets a face detection mode of the face detection unit to a face detection mode having a relatively highest detection precision of the plural face detection modes regardless of a face detection mode at a time when the image-pickup preparation is set, in response to the image-pickup preparation set by the user through the operation unit while the face detection unit repeats a detection operation of detecting a face region.