To generate no abrasion caused by a contact of a rib provided on a belt and a position control member, to require no complex roller attitude control mechanism and to stably solve an approaching and a meander of an endless belt.

The endless belt device is provided with a driving roller 2; an endless belt 1 wound on a driven roller 3; and a belt 1 approaching restriction means. The restriction means comprises a magnetized rib 7 circumferentially provided on a back surface at one end in a width direction of the belt 1; and magnets 4, 5 disposed while clamping the rib 7. The same pole surface of the magnets 4, 5 as a magnetic pole of the rib 1 is opposed to the rib. When a tension balance is destroyed and an approaching force FyL in a minus Z direction is generated, the rib is approached to the magnet 5, a resiliency FmL is generated between an N pole of the magnet and an N pole of the rib and an approaching of the belt to the minus Z direction is inhibited. Similarly, when an approaching force FyR in a plus Z direction is generated, a resiliency FmR is generated between an S pole of the rib and an S pole of the magnet 4 and an approaching of the belt to the plus Z direction is inhibited.