To provide a resin material which does not cause the degradation due to ultraviolet rays of sunlight and the degradation due to an increase in spoilage bacteria even if the resin material is left outside, and to provide a product.

After a coal powder, such as charcoal powder, bamboo charcoal powder, and active coal powder, and one or more of a polyethylene resin, a polypropylene resin, and a pet resin are melted together, 3-10 pts.wt. of coal powder is mixed with 10 pts.wt. of resin to obtain coal powder-mixed resin pellets. The product obtained by forming the pellets adsorbs sunlight such as ultraviolet rays and converts it into thermal energy, and hence does not cause the degradation of the resin and suppresses an increase in spoilage bacteria.