Fixing unit and image forming apparatus

A fixing unit configured to fix a toner image on a recording material by heating the recording material with the toner image formed thereon, the fixing unit comprising:

• a rotary member including a conductive layer and having a tubular shape extending in a longitudinal direction;
• a coil configured to generate an alternating magnetic field to generate heat in the conductive layer;
• and
• a core disposed inside the rotary member and configured to guide magnetic field lines of the alternating magnetic field,
• wherein the core is constituted by a plurality of divided cores aligned along the longitudinal direction, and
• at least one of the plurality of divided cores is formed in a columnar shape having an aspect ratio of 1:5 or less between a maximum width in a cross section orthogonal to the longitudinal direction and a length in the longitudinal direction, and is made of compacted magnetic core material disposed such that a hard-magnetization axis thereof is oriented in an intersection direction intersecting the longitudinal direction.