PURPOSE: To wash the whole surface of an edible root such as burdock, uniformly, by using an apparatus having pairs of pinch rollers which rotate the object to be washed with washing brushes about an axis perpendicular to the transfer direction.

CONSTITUTION: Plural pairs of rotary brushes 4 and 5, each pair being arranged vertically, are aligned along the transfer direction of the nearly cylindrical object (a) to be washed. Plural pairs of pinch rollers 7 and 8, each pair being arranged vertically, are positioned at arbitrary positions between the pairs of the brushes 4 and 5. The upper and the lower pinch rollers are freely movable along vertical direction, and the gap between them can be adjusted according to the size of the object (a) to be washed. Some of the pinch rollers 7 and 8 are apiral pinch rollers 7a and 8a, which rotate the object (a) about an axis perpendicular to the transfer direction of the object (a). Consequently, the whole surface of the object (a) can be washed uniformly with the brushes 4 and 5.