The utility model discloses a reaction cavity which is used for the dry-etching of base plates. The reaction cavity comprises a reaction cavity body, a first electrode, and a second electrode, wherein the first and second electrodes are oppositely arranged and vertically fixed inside the reaction cavity body. An electric field is generated between the first electrode and the second electrode. The first and second electrodes are vertically placed inside the reaction cavity. During the dry etching, the etching of the two base plates can be carried out at the same time, and the etching efficiency is improved. Moreover, the electrodes can be protected from the etching of plasma, thereby indirectly improving the usage rate of the plasma. Meanwhile, the etched base plates are vertically place, thereby reducing the probability that particles fall onto the surfaces of the base plates.