A noise processing apparatus comprising: a first measuring unit configured to measure a first potential difference signal between a first electrode that is arranged at a location other than a steering unit in an apparatus and a second electrode that is used as a reference electrode; a second measuring unit configured to measure a second potential difference signal between the second electrode and a third electrode that is arranged on the steering unit in the apparatus; an intensity calculating unit (103, 401) configured to calculate, at predetermined periods, first intensity values each corresponding to each predetermined period of the first potential difference signal and second intensity values each corresponding to the each predetermined period of the second potential difference signal; a difference calculating unit (104, 402) configured to calculate differences between the first intensity values and the second intensity values, respectively; a correction unit (105, 403) configured to correct at the each predetermined period of the first potential difference signal and/or the second potential difference signal by using each corresponding difference calculated by the difference calculating unit such that the difference between the first intensity values and the second intensity values is cancelled out; a differential signal calculating unit (106, 403, 404) configured to calculate a differential signal indicating a difference between the first potential difference signal and the second potential difference signal, the first potential difference signal used by the differential signal calculating unit being a corrected first potential difference signal when the first potential difference signal is corrected, and the second potential difference signal used by the differential signal calculating unit being a corrected second potential difference signal when the second potential difference signal is corrected; and an output processing unit (107, 405) configured to output the differential signal calculated by the differential signal calculating unit. a first measuring unit configured to measure a first potential difference signal between a first electrode that is arranged at a location other than a steering unit in an apparatus and a second electrode that is used as a reference electrode; a second measuring unit configured to measure a second potential difference signal between the second electrode and a third electrode that is arranged on the steering unit in the apparatus; an intensity calculating unit (103, 401) configured to calculate, at predetermined periods, first intensity values each corresponding to each predetermined period of the first potential difference signal and second intensity values each corresponding to the each predetermined period of the second potential difference signal; a difference calculating unit (104, 402) configured to calculate differences between the first intensity values and the second intensity values, respectively; a correction unit (105, 403) configured to correct at the each predetermined period of the first potential difference signal and/or the second potential difference signal by using each corresponding difference calculated by the difference calculating unit such that the difference between the first intensity values and the second intensity values is cancelled out; a differential signal calculating unit (106, 403, 404) configured to calculate a differential signal indicating a difference between the first potential difference signal and the second potential difference signal, the first potential difference signal used by the differential signal calculating unit being a corrected first potential difference signal when the first potential difference signal is corrected, and the second potential difference signal used by the differential signal calculating unit being a corrected second potential difference signal when the second potential difference signal is corrected; and an output processing unit (107, 405) configured to output the differential signal calculated by the differential signal calculating unit.