the purpose of the present invention is to provide a electric generator which has a simple structure while sufficiently suppressing cogging torque . a electric generator is constituted by a rotor section comprising a plurality of protrusions which is arranged linearly with constant pitch at mutually separated positions sandwiching permanent magnets , and a stator section which has a stator member comprising stator yokes , permanent magnets facing the permanent magnets , and protrusions which protrude closer to the rotor section than the permanent magnets and are arranged linearly with constant pitch at mutually separated positions sandwiching the permanent magnets , the stator member being configured such that the protrusions and the protrusions are shifted from each other by a half pitch between adjoining stator members . further , the rotor section - side protrusions may be shifted by a half pitch instead of the stator section - side protrusions .