An impact tool has a mechanical structure to strike an anvil with a striking force appropriate for a task. An impact tool includes a motor, a hammer rotatable by the motor, an anvil that receives a tip tool and is strikable by the hammer in a rotation direction, an elastic member having a front end supporting the hammer and being extendable and contractable in a front-rear direction to apply an elastic force to the hammer toward the anvil, and a positioner supporting a rear end of the elastic member. The positioner changes a support position of the positioner supporting the rear end of the elastic member in the front-rear direction.