To improve electromagnetic wave absorption characteristics, and to improve heat resistance at low costs while providing sufficient mechanical strength by providing heat-resistant resin at one or entire part of the surface of a composite magnetic material being used as a core.

In a composite magnetic material 1 being used as the core of an electromagnetic interference suppression body 11, flat or needle-shaped soft magnetic body powder and a resin matenal of an organic bonding agent are prepared by specific weight ratio and a creation method. Also, silicon resin is used as heat-resistant resin 5 for covering a surface. The thickness of the composite magnetic material 1 being used as the core and the heat-resistant resin layer 5 should be set to 1 and 0.5 mm, respectively. In such electromagnetic interference suppression body 11, excellent characteristics are obtained. Also, although the heat-resistant temperature of the composite magnetic matenal of a conventional electromagnetic interference suppression body 11 was 85°C, the heat-resistant temperature can be increased up to 120°C in the electromagnetic interference suppression body 11. Furthermore, a material and a process required for preparing the electromagnetic interference suppression body are not special, so that cost increase is slight.