To reduce the leakage of a sprayed treatment liquid outside a sprayer in spraying and to prevent a treated plate from being hurt the both of that have occurred in the conventional sprayer.

The sprayer has a conveyance means for conveying the plate and a spry means for spraying the treatment liquid on the upper and lower surfaces of the conveyed plate. The sprayer is divided into at least a carrying-in side spray seal chamber, a main spray chamber, and a carrying-out side spray seal chamber. By installing the spray means of the carrying-in side spray seal chamber and the carrying-out side spray seal chamber while being slanted to the side of the main spray chamber, the leakage of the sprayed treatment liquid outside the sprayer is reduced, and the plate is made preventable from being hurt.