A generator is provided comprising a driving shaft (1) rotated by an external driving force, a first rotator disk (5L) mounted to the driving shaft (1) and having a magnetic pole face thereof provided with N poles and S poles of permanent magnets (6NL and 6SL), a second rotator disk (5R) mounted to the driving shaft (1) to be distanced from the first rotator disk (5L) and having a magnetic pole face thereof provided with permanent magnets (6NR and 6SR) facing the magnetic pole face of the first rotator disk (5L), and a stator (10) having a group of first windings (L1 to L6) and a group of second windings (L7 to L12) mounted on a ring core (11) thereof which is disposed between the first rotator disk (5L) and the second rotator disk (5R). This can improve the efficiency of power generation and the efficiency of heat radiation.
