75 a pair of drive motors brush driving means 87 88 for rotatably driving the rotating brushes 74 75 respectively a pair of drive rollers 60 61 for rotatably driving a wafer w while it supporting thereon and another drive motor wafer driving means 65 the wafer w is gripped between the rotating brushes 74 75 with its outer peripheral portions supported on the drive rollers 60 61 while keeping this condition the drive motor 65 is driven to rotate the wafer w by means of the drive rollers 60 61 and at the same time the drive motors 87 88 are driven to rotate the rotating brushes 74 75 whereupon the wafer w is cleaned on its opposite sides by the rotating brushes 74 75 cleaning with hydrofluoric acid hf hf concentration 1 by weight 25 u00b0 c 3 minutes ozone containing pure water a supply of 2 liters per minute 25 u00b0 c 3 minutes ozone concentration 2 ppm cleaning bath size common to hf cleaning and ozone containing pure water cleaning 320 u00d7 30 u00d7 280 mm under the condition specified above the sample wafer was cleaned with hf then the hf cleaned sample wafer was rinsed with the ozone containing pure water and after that the washed sample wafer was cleaned by scrubbing with rotating brushes of the brush scrubber shown in fig3 while pure water is supplied to the rotating brushes the brush scrubbed wafer was then subjected to a post cleaning process and a drying.