To inexpensively wash dirty balls by providing a ball washing device having a large treatment capacity with a simple structure.

This device has a liquid tank 22 for housing a washing solution 3, which has a circularly formed bottom surface; an impeller 29 for partitioning the liquid tank 22 into a plurality of areas, which is formed by a plurality of partitioning plates 28 radially provided from the shaft center of a rotating shaft 25 concentric to the liquid tank 22; and a motor 21 for driving the rotating shaft 25. Dirty balls 1 from an input hopper 36 are put into each area of the impeller 29, the balls 1 are dipped and washed in the washing solution 3 by the rotation of the impeller 29, and after washing, the balls are discharged through a discharge guide passage 39.