It is intended to provide an agent for treating fungi which is capable of controlling the production cost while using a microorganism with high safety, and also maintaining an adhesion state on a surface of a target for a predetermined period of time or longer during use, and a method for treating fungi. The agent for treating fungi is characterized by containing a microorganism-containing liquid obtained by adding water to powder prepared by mixing a Bacillus sphaericus microorganism, a Bacillus subtilis microorganism, or a Bacillus thuringiensis microorganism with livestock manure treated at a high temperature between 60° C. and 150° C., a surfactant, and a propellant. The agent for treating fungi is characterized in that, preferably, the surfactant is at least one type selected from the group consisting of sodium lauryl sulfate, polyoxyethylene cetyl ether, and potassium fatty acid, and the propellant is LP gas.
