An antiviral agent that contains as an active ingredient a particle of at least one kind of iodide composed of iodine and an element shown in Period 4 to Period 6 and Group 8 to Group 15 of a periodic table or at least one kind of monovalent copper compound. The antiviral agent can be incorporated into a variety of products. The antiviral agent can inactivate a wide range of viruses. The antiviral agent can be designed at a higher degree of freedom in terms of its constituents as compared to conventional antiviral agents. In addition, the antiviral agent can readily exhibit and maintain its antiviral activity because it does not require any pretreatments or special washing processes.
