A dirt separator for a vacuum cleaner includes a chamber having an inlet through which dirt-laden fluid enters and an outlet through which cleansed fluid exits the chamber. A disc located at the outlet rotates about a rotational axis and comprises holes through which the cleansed fluid passes. The disc comprises a perforated region and a non-perforated region. The holes are then formed in the perforated region, and the width of the non-perforated region is no less than the diameter of the inlet.