PROBLEM TO BE SOLVED: To provide a method for exterminating adult mosquitoes that maintains excellent pest extermination effect by suppressing reduction in airborne concentration of a chemical after releasing the chemical, promotes diffusion of the chemical by holding the chemical in the air, has sufficient effect against the mosquitoes lurking in a hiding place, and suppresses a wasteful use of the chemical, thereby having high safety.SOLUTION: The method for exterminating pests using a treatment chemical containing an insecticide and/or a repellent is characterized by setting the airborne residual rate of the amount of the treatment chemical in the treating space to 5% or more after two hours from the start of the treatment.
