A calibration system includes: a first position detection unit, provided in a working machine having a working apparatus, for detecting the position of an object whose position is to be detected and outputting the detected position; and a processing unit which, by using first position information that is information pertaining to the prescribed position of the working machine detected by the first position detection unit and second position information that is information pertaining to the prescribed position detected by a second position detection unit while the working machine is in the same orientation as when the first position detection unit detected the prescribed position, either obtains conversion information that is used to convert the position detected by the first position detection unit from the coordinate system of the first position detection unit to a coordinate system different from that of the first position detection unit and outputs the obtained information, or obtains conversion information that is used to convert the position detected by the second position detection unit from the coordinate system of the second position detection unit to a coordinate system different from that of the second position detection unit and outputs the obtained information.