EMI-proof server chassis preventing EMI on an electronic component, includes a chassis and a double aperture flexible piece. The chassis includes a connection portion connected to the chassis, a first engagement portion and a second engagement portion. The first engagement portion and the second engagement portion are connected to and disposed on two sides of the connection portion. The first engagement portion and the second engagement portion are parallelly prolonged, and substantially opposite to each other. The double aperture flexible piece, shaped as a curvature plate, has a first aperture and a second aperture on two sides. The first engagement portion and the second engagement portion are engaged to the first aperture and the second aperture respectively, and the portion of the double aperture flexible piece between the first aperture and the second aperture is curved toward the electronic component, and contact with the electronic component.