PROBLEM TO BE SOLVED: To provide an insect repellent which has a sufficient effect to repell harmful insects, is highly safe to a human body and highly stable, and can be used easily at home.SOLUTION: The insect repellent contains only a silicone based compound represented by formula (1), as an effective component, and used for larvas or imagos of Orthoptera or Diptera. In the formula (1), R1, R2 and R3 each represents a hydrogen atom, and m, n and o are natural numbers 0-100.