WASHING-OUT DEVICE AND WASHING-OUT METHOD

Provided are a washing device and a washing method that achieve prevention of development scum adhesion, development uniformity, and development speed at the same time. This washing device performs development using a washing solution while transporting the flexographic printing plate precursor after imagewise exposure. The washing device includes a transport unit that transports the flexographic printing plate precursor along a predetermined transport path and a development unit that performs development on the flexographic printing plate precursor. The development unit includes a brush which is used for the development and a driving unit which controls rotation of the brush around a rotation axis and movement of the brush. The brush removes an unexposed portion of the flexographic printing plate precursor to perform the development, and the rotation axis of the brush is a fixed axis passing through one point in the brush. The driving unit rotates the brush in a state in which the rotation axis of the brush passes through a surface of the flexographic printing plate precursor, and moves the rotation axis of the brush in at least one direction intersecting the rotation axis.