A reaction chamber and a semiconductor processing device, comprise a Faraday shielding ring (21) made of a magnetic insulation material and an insulating ring (22) made of an insulating material; the Faraday shielding ring (21) is provided with a slot thereon passing through a ring surface thereof in an axial direction; both the Faraday shielding ring (21) and the insulating ring (22) are disposed in the reaction chamber surrounding an inner peripheral wall of the reaction chamber, and the Faraday shielding ring (21) is stacked on the insulating ring (22) in a vertical direction. A shielding ring (211) is disposed surrounding an inner peripheral wall of the insulating ring (22), the shielding ring (211) is connected to an area of a lower surface of the Faraday shielding ring (21) adjacent to a center of the reaction chamber, and the shielding ring (211) is made of a magnetic insulation material and provided with a slot thereon passing through a ring surface thereof in an axis direction. The reaction chamber and the semiconductor processing device can not only avoid or reduce the risk of sparking, but also reduce the pollution of the reaction chamber caused by the flaking off of metal particles; and in addition, it is possible to increase an inner diameter and an available space of the reaction chamber.