A calibration device performs a calibration between a plurality of imaging devices, each of which outputs field-of-view information which is information on a field-of-view of the imaging device itself. The field-of-view information contains a bitmap image and a range image. The calibration device includes: a state estimation part configured to detect, in a field of view of a first imaging device, an image of a second imaging device, and estimate a relative position and a relative attitude of the second imaging device with respect to the first imaging device, based on the detected image; and a transformation information calculation part configured to calculate transformation information between a coordinate system of the first imaging device and a coordinate system of the second imaging device, based on the estimated relative position and relative attitude.