To efficiently prevent snow cover and freezing by using composite material added artificial graphite of a specified carbon particle diameter, or natural graphite particles to base material composed of organic rubber.
Natural graphite added coal tar pitch as binder is kneaded, formed, sintered, and ground, for obtaining natural graphite powder having a particle diameter of at least 1 mm, for example, 2-5 mm, which is added to polyurethane/NBR rubber to be press/heat-formed for obtaining a sheet. Carbon to be added must be artificial graphite or natural graphite powder. Ceramic does not improve heat properties and good thawing properties of snow and ice is not developed. Although metal particles show improvement in snow and ice thawing properties, its corrosiveness prevents outdoor use for an extended period. The artificial graphite powder made by grinding artificial graphite material, which is graphitized from petroleum coke material or the like, can be used.