In a heat fixing member which is a seamless type cylindrical heat fixing
member having an elastic layer, the elastic layer is mixed with carbon
fibers, and the elastic layer has a thermal conductivity of 1.0 W/(mK) or
more in the thickness direction thereof. A heat fixing member is provided
which is more improved in the thermal conductivity in the thickness
direction, can efficiently supply heat to the heating object (recording
medium) at the time of high-speed printing, can give fixed images having
a high glossiness in virtue of the elastic layer, which has secured a
sufficient flexibility. A high-performance heat fixing assembly is also
provided which can conduct sufficient heat to toner images even if the
dwell time is shortened.