A high-precision magnet encoder in which high-order harmonic components can be suppressed without increasing the number of lead wires connecting magnetic field detecting elements to a signal processing circuit. Hall sensors of phase A1, phase B1, phase A2 and phase B2 are arranged sequentially around a permanent magnet 2 at intervals of 90 degrees via an air gap. Hall sensors of phase C1, phase D1, phase C2, phase D2 are arranged at positions 60 degrees away from the Hall sensors of phase A1, phase B1, phase A2 and phase B2, respectively. Connection is made between the positive output terminals of a set of Hall sensors located at positions 60 degrees away from each other and between their negative output terminals.