A vacuum cleaner is disclosed, and this cleaner maintains sucking power at a high level while it resists lowering the suction force although it sucks dust. The vacuum cleaner includes a cylindrical dust collecting case which takes air in sucked by an electric air blower and including dust. The case includes a suction port through which the air including dust flows into the case along a tangent line, and a dust collector communicates with the port. A dust filter in the case is placed in an air-duct through which the case communicates with the electric air blower. This structure allows whirling airflow in the case to whirl continuously in the case, so that dust can be removed from the filter even if the dust attaches to the filter. As a result, sucking airflow can be always secured.