Magnetic sensor

The invention provides a magnetic sensor capable of eliminating an AC component contained in an ambient magnetic field. A magnetic sensor (1) is provided with: an ambient magnetic field sensor (S0) for generating an ambient magnetic field signal (F0); a detection magnetic field sensor (S1) for generating a detection magnetic field signal (F1); a capacitor (C) for extracting a DC component by removing an AC component of a predetermined frequency band from the ambient magnetic field signal (F0); and a compensation coil (31) for applying a cancellation magnetic field to the detection magnetic field sensor (S1) on the basis of the DC component. A compensation coil (41) for applying a cancellation magnetic field to the detection magnetic field sensor (S1); and a band-pass filter (91) for removing at least an AC component of a predetermined frequency band from the detection magnetic field signal (F1). As a result, the AC component contained in the ambient magnetic field can be eliminated regardless of the positions