To provide a snow melting agent, inexpensive, generating no environmental pollution, having high snow melting efficiency and easily handleable.

The snow melting agent is actualized by dissolving powder of atomic carbon comprising a carbon atom simple substance or a combination of some carbon atoms and calcium in water, and isolating the atomic carbon and calcium in negative ionic water maintained at ≥pH 8 with hydrogen ions. The atomic carbon used in the snow melting agent is obtained by heating an organic substance in a non-oxygenic atmosphere at a predetermined temperature and thermally decomposing components except carbon in the atmosphere and the organic substance one by one from the components having lower decomposition temperature at a temperature of ≤600°C to individually separate the components.