A dust collector for electric power tool includes a casing, a ring-shaped suction opening, a dust collecting route, and a filter. The suction opening protrudes forward from the casing. The tool bit of the electric power tool is insertable into the suction opening in a state where the suction opening is brought into contact with a surface to be processed. The dust collecting route is formed within the casing and guides an air suctioned from the suction opening to a dust collection portion in the casing. The filter is disposed in the dust collection portion to capture dust suctioned with the air. On the dust collecting route in the dust collection portion, a first filter and a second filter are disposed. The first filter includes a dust collecting chamber partitioned inside the dust collection portion. The second filter is arranged outside the first filter independently from the first filter.