Fixing device, image forming apparatus and fixing method

In accordance with one embodiment, a fixing device comprises a pressing roller configured to be rotationally driven by a motor; an endless fixing belt configured to be driven to rotate through the rotation of the pressing roller; a fixing pad configured to be contacted with the inner periphery of the fixing belt and be pressed against the pressing roller to form a fixing nip; a lubricant configured to be coated on the inner peripheral surface of the fixing belt; an exciting coil configured to generate a magnetic field; a magnetic shunt alloy member configured to abut along one part of the inner peripheral surface of the fixing belt; a shield member configured to face the inner side of the magnetic shunt alloy member; and a flow-out prevention section configured to prevent the lubricant from flowing into a gap between the magnetic shunt alloy member and the shield member.