A calibration apparatus calibrates parameters of imaging apparatuses which are disposed at different positions and image a common three-dimensional space. The calibration apparatus includes: an obtaining circuit which obtains videos captured by the imaging apparatuses and each including frames; an extraction circuit which extracts feature points from the frames included in the videos, the feature points including first feature points extracted from first frames included in the videos and second feature points extracted from areas containing an image of a moving object in second frames included in the videos and different from the first frames; a matching circuit which performs matching using the feature points, the matching including matching between the first feature points and matching between the second feature points; and a calibration circuit which calculates parameters of the imaging apparatuses based on first matching results obtained through the matching by the matching circuit.