Fixing member and heat fixing device

A fixing member includes a substrate having an endless shape; and an elastic layer on an outer peripheral surface of the substrate, the elastic layer containing a silicone rubber and fillers dispersed in the silicone rubber, a content of the fillers with respect to the elastic layer being 35 vol % or more and 50 vol % or less. The fillers includes at least a first filler and a second filler. The first filler is at least one selected from the group consisting of: magnesium oxide; and zinc oxide. The second filler is at least one selected from the group consisting of metal silicon and silicon carbide. A proportion of a sum of the first filler and the second filler to a total amount of the fillers in the elastic layer is 90 vol % or more. Further, the average of 6 sets of representative coefficient A is 1.4 or more.