Abstract: An object is to improve deposition of silicon on a base portion of a silicon filament. A filament holder (10A) includes a filament holding portion (12A) which has a substantially truncated cone shape. The filament holding portion (12A) has, in a top surface (12a) thereof, a filament insert hole (13A) configured to hold a silicon filament (4A). The angle (0) between the axis and the generatrix of the substantially truncated cone shape is not less than 10 degrees and not more than 30 degrees. The margin width (L) of the filament holding portion (12A) between the outer periphery of the top surface (12a) of the filament holding portion (12A) and an inner wall surface (13a), which is contacted by the silicon filament (4A) of the filament insert hole (13A) is not more than 3 mm at at least one location.

Abstract: A polycrystalline silicon rod is formed of polycrystalline silicon deposited radially around a silicon core line and is characterized by, in a cross-section that is a perpendicular cut in respect to the axial direction of a cylindrical rod, a ratio of surface area covered by coarse crystal particles having a diameter of 50 ?m or greater is 20% or more of the crystal observed at the face, excluding the core line portion.

Abstract: An object of the present invention is to provide a stretched porous film having all of air permeability, water resistance, and flexibility. A stretched porous film in accordance with an embodiment of the present invention contains a resin composition containing a specific polyethylene-based resin and a thermoplastic elastomer at a certain mass ratio, and has a water vapor transmission rate of not less than 1400 g/m·.24 h.

Abstract: A polycrystalline silicon rod is formed of polycrystalline silicon deposited radially around a silicon core line and is characterized by, in a cross-section that is a perpendicular cut in respect to the axial direction of a cylindrical rod, a ratio of surface area covered by coarse crystal particles having a diameter of 50 ?m or greater is 20% or more of the crystal observed at the face, excluding the core line portion.