An aftertreatment apparatus and method for printing plates which have been imagewise exposed having an exposure station and a heating station which are arranged one behind the other in the direction of conveyance of the printing plates along a conveyance track. The exposure station contains a linear LED arrangement which in turn has at least two rows of LED modules which are offset with respect to one another. The LED modules are made up of a plurality of light-emitting diodes. The housing of the heating station is thermally insulated on three sides and is open at the bottom in the direction of a reflector table over which the printing plates are passed.