An image processing apparatus receives an input specifying a target in a first captured image group that is obtained by slicing a three-dimensional body into captured images at a first point in time, extracts feature points surrounding the specified target from the captured images of the first captured image group, specifies slice positions of each of the feature points that are extracted in captured images of a second captured image group that is obtained by slicing the three-dimensional body into the captured images at a second point in time, and outputs an image corresponding to a slice position range specified based on the specified slice positions of each of the extracted feature points, and corresponding to a range on a first plane specified based on positions of each of the extracted feature points on a second plane.