An image processing device includes: a road surface detecting section to detect a road surface region from an input image based on a shot image obtained by shooting with a camera; a time-series verifying section to perform time-series verification to verify a result of detection of the road surface region in the input image in a time-series manner; a detection region selecting section to set a detection region for detection of an object in the input image according to the result of detection of the road surface region by the road surface detecting section and a result of the time-series verification by the time-series verifying section; and a detecting section to detect the object in the detection region.