To obtain a water-based coating material containing an antimicrobial agent hardly soluble in water, especially hinokitiol and/or a metal complex thereof, in an amount sufficient for exhibiting the properties such as antimicrobial activities, stably formulated therewith without damaging the properties originally possessed by the water-based coating material by an inexpensive method.

This water-based coating material is characterized in that the coating material contains the antimicrobial agent hardly soluble in the water, in a resin which is a main element for forming a coating film.