An antimicrobial and antiviral composition, a method of producing the same, and the like are provided, which are capable of exhibiting an excellent antimicrobial and antiviral properties over a long time in the application for various uses. The antimicrobial and antiviral composition contains cuprous oxide particles having a BET specific surface area of 5 to 100 m2/g and a saccharide having an aldehyde group, in which the content of the saccharide with an aldehyde group is 0.5 to 10 mass part based on the cuprous oxide particles of 100 mass part. The method produces this composition.
