The invention discloses a window blocking device of an etching machine and belongs to the technical field of etching in the semiconductor and panel display industry. The window blocking device comprises a transparent blocking object (2) installed on the inner wall of an etching machine box body (5) and located on the front side of a window (1), wherein the transparent blocking object (2) is a corrosion-resistant part. The window blocking device of the etching machine prevents a plasma from damaging an etching terminal point detector window or other windows formed in the etching machine in the etching process and meanwhile does not influence light collection, production cost is effectively reduced, and the window blocking device is especially suitable for a dry etching production device.