Magnetic members of a high-sensitivity magnetoimpedance element and a low-sensitivity magnetoimpedance element are connected to each other in series, and the strength and direction of an external magnetic field is detected on the basis of an impedance variation of this series circuit. The output of a magnetic field detection sensor mainly reflects an impedance variation of the high-sensitivity magnetoimpedance element in a weak magnetic field range, and mainly reflects an impedance variation of the low-sensitivity magnetoimpedance element in a strong magnetic field range, whereby continuous detection is enabled in a wide range from a weak magnetic field to a strong magnetic field.