A dust collection device, that collects dust particles generated by an impact tool, has a feature that enables the attachment of the device to the impact tool, which is not provided with an attachment section for the device. The dust collection device has a tool body and an auxiliary handle, attached removably to the tool body, and is attached to an electric hammer that, in the lengthwise direction, linearly operates a tool bit mounted to the tip region of the tool body, and collects dust generated by the electric hammer. The dust collection device has: a dust collection unit that has a dust intake port at the tip; a dust collection hose, connected to the dust collection unit, for transferring dust to the downstream side; and a hose-holding unit that holds the dust collection hose. The hose-holding unit can be attached to and removed from the auxiliary handle.