An impact tool includes a motor, a hammer casing with an opened rear end and a disk-shaped member coupled to the hammer casing to close the opened rear end and to rotatably support a spindle. A first engagement member is formed on an outer face of the disk-shaped member. A second engagement member is formed on an inner face of the recess and engaging with the first engagement member to restrict a movement of the hammer casing in a second direction parallel to a rotation axis of the spindle. A third engagement member is formed on an outer face of the hammer casing. A fourth engagement member is formed on an inner face of the housing body and engaging with the third engagement member so as to restrict a movement of the hammer casing in the first direction.