A power measurement apparatus configured to measure power consumed at a load (9; R1) connected with a power source via a connecting line, the apparatus comprising: a) a magnetic film module (11, Rmr) arranged so that a longitudinal direction of the magnetic film module is parallel to current flowing in the connecting line; b) an adjuster (P1, P2, Pn; B1, B2, Bn, 16) configured to adjust a pass-frequency and a phase of a current flowing through the adjuster from the magnetic film module; c) a measurement resistance serially-connected to the magnetic film module; and d) a voltage detector configured to detect a voltage between a pair of terminals (10ta, 10tb) of the magnetic film module, wherein the adjuster (P1, P2, Pn; B1, B2, Bn, 16) comprises: a1) a plurality of parallel-connected band-pass-filters (B1, B2, Bn) connected to the one terminal of the magnetic film module; a2) a plurality of phase adjusters (P1, P2, Pn), each of which being serially-connected to a respective band-pass-filter of the plurality of band-pass-filters (B1, B2, Bn); and a3) a switch configured to select one of outputs from the phase adjusters (P1, P2, Pn), wherein the adjuster (P1, P2, Pn; B1, B2, Bn, 16) is configured to adjust the phase so as to maximize a detected voltage from the voltage detector. a) a magnetic film module (11, Rmr) arranged so that a longitudinal direction of the magnetic film module is parallel to current flowing in the connecting line; b) an adjuster (P1, P2, Pn; B1, B2, Bn, 16) configured to adjust a pass-frequency and a phase of a current flowing through the adjuster from the magnetic film module; c) a measurement resistance serially-connected to the magnetic film module; and d) a voltage detector configured to detect a voltage between a pair of terminals (10ta, 10tb) of the magnetic film module, wherein the adjuster (P1, P2, Pn; B1, B2, Bn, 16) comprises: a1) a plurality of parallel-connected band-pass-filters (B1, B2, Bn) connected to the one terminal of the magnetic film module; a2) a plurality of phase adjusters (P1, P2, Pn), each of which being serially-connected to a respective band-pass-filter of the plurality of band-pass-filters (B1, B2, Bn); and a3) a switch configured to select one of outputs from the phase adjusters (P1, P2, Pn), wherein the adjuster (P1, P2, Pn; B1, B2, Bn, 16) is configured to adjust the phase so as to maximize a detected voltage from the voltage detector. wherein the adjuster (P1, P2, Pn; B1, B2, Bn, 16) comprises: a1) a plurality of parallel-connected band-pass-filters (B1, B2, Bn) connected to the one terminal of the magnetic film module; a2) a plurality of phase adjusters (P1, P2, Pn), each of which being serially-connected to a respective band-pass-filter of the plurality of band-pass-filters (B1, B2, Bn); and a3) a switch configured to select one of outputs from the phase adjusters (P1, P2, Pn), a1) a plurality of parallel-connected band-pass-filters (B1, B2, Bn) connected to the one terminal of the magnetic film module; a2) a plurality of phase adjusters (P1, P2, Pn), each of which being serially-connected to a respective band-pass-filter of the plurality of band-pass-filters (B1, B2, Bn); and a3) a switch configured to select one of outputs from the phase adjusters (P1, P2, Pn), wherein the adjuster (P1, P2, Pn; B1, B2, Bn, 16) is configured to adjust the phase so as to maximize a detected voltage from the voltage detector.