Antimicrobial finishings of industrial materials, products, foods, clothings and shelters have been remarkably developed in Japan and is now progressing. In addition, frequent occurrence of the infectious diseases such as Vero cytotoxin-producing Escherichia coli O-157, Legionella pneumophila, Staphylococcus aureus and resistant bacteria against antibiotics brings a boom of antimicrobial finishing and goods. The first aim of antimicrobial finishing for industrial materials and products is to protect from microbial deterioration and degardation. The second is to inhibit the growth of harmful microbes on the surfaces of industrial products. The third is to maintain hygiene in living environment. In future, highly functional antimicrobial chemicals will be developed and a greater number of industrial products will be processed with the chemicals. However, it is necessary for the chemicals processed to change into biodegradable and environmentally friendly substances immediately in a moderate condition.