A current measurement method comprising the step of: providing, at part of a conductor to which a measurement target current flows in a first direction, a nonconductive area (2; 8; 13; 7a, 7b; 7c, 7d) to which the measurement target current does not flow as a direction change area (2; 8; 13; 9a; 9b; 7a, 7b; 7c, 7d) that changes a flowing direction of the measurement target current from the first direction to another direction, around the nonconductive area; the current measurement method being characterised by further comprising the steps of: arranging at least one magnetic detection element (3, 3a, 3b), having a magnetic field detection sensitivity only in one direction, near the nonconductive area such that the direction of the magnetic field detection sensitivity is directed in the first direction of the measurement target current; causing the magnetic detection element to detect a magnetic field generated by the measurement target current whose flowing direction is changed by the direction change area (2; 8; 13; 9a; 9b; 7a, 7b; 7c, 7d), the magnetic field being a magnetic field component of a bypass current flowing outside the nonconductive area, which is directed in the first direction of the measurement target current; and estimating an amount of the measurement target current from an output of the magnetic detection element. providing, at part of a conductor to which a measurement target current flows in a first direction, a nonconductive area (2; 8; 13; 7a, 7b; 7c, 7d) to which the measurement target current does not flow as a direction change area (2; 8; 13; 9a; 9b; 7a, 7b; 7c, 7d) that changes a flowing direction of the measurement target current from the first direction to another direction, around the nonconductive area; the current measurement method being characterised by further comprising the steps of: arranging at least one magnetic detection element (3, 3a, 3b), having a magnetic field detection sensitivity only in one direction, near the nonconductive area such that the direction of the magnetic field detection sensitivity is directed in the first direction of the measurement target current; causing the magnetic detection element to detect a magnetic field generated by the measurement target current whose flowing direction is changed by the direction change area (2; 8; 13; 9a; 9b; 7a, 7b; 7c, 7d), the magnetic field being a magnetic field component of a bypass current flowing outside the nonconductive area, which is directed in the first direction of the measurement target current; and estimating an amount of the measurement target current from an output of the magnetic detection element. arranging at least one magnetic detection element (3, 3a, 3b), having a magnetic field detection sensitivity only in one direction, near the nonconductive area such that the direction of the magnetic field detection sensitivity is directed in the first direction of the measurement target current; causing the magnetic detection element to detect a magnetic field generated by the measurement target current whose flowing direction is changed by the direction change area (2; 8; 13; 9a; 9b; 7a, 7b; 7c, 7d), the magnetic field being a magnetic field component of a bypass current flowing outside the nonconductive area, which is directed in the first direction of the measurement target current; and estimating an amount of the measurement target current from an output of the magnetic detection element.