PROBLEM TO BE SOLVED: To provide a method for eliminating cockroaches, by which the effect of the elimination lasts for a long period with a few treatments.SOLUTION: The method of eliminating cockroaches uses a total releasing type of agent containing hydroplane and an insecticide. The hydroplane and the insecticide are applied to a specific space through the total releasing type agent. After the initial application, at least one succeeding application is made within 20 to 50 days.