PURPOSE: To promote the evaporation of emulsified water, by electrically earthing at least one metal roller among a large number of rollers constituting inking arrangement and connecting a high voltage generator to a roller electrode.

CONSTITUTION: A roller 12 made of a metal is earthed electrically. An electrode roller 28 is contacted with the roller 12 through an ink membrane under proper pressure and is a freely rotating roller rotating so as to follow the rotary power of the roller 12. When the electrode roller 28 rotates with the rotation of the roller 12, high voltage is applied to the ink membrane interposed between the roller 12 and the electrode roller 28 by a high voltage generator 23. Whereupon, fine water droplets of dampening water are flocculated to grow and a large amount of surface water is generated in the nip parts of form rollers 17, 18 and the roller 12. Therefore, evaporation is promoted and it is unnecessary to evaporate and remove dampening water penetrated in inking arrangement by a large number of ink distributing rollers and the number of the rollers can be reduced thereby contributing to cost reduction.