A device is provided which is capable of evenly etching the entire surface of a silicon core wire. An etching device (1) for a silicon core wire (C1, C2, C3) includes: an etching bath (11, 12) for holding an etching solution (L1, L2); and a plurality of core wire support members (31) for supporting the silicon core wire (C1, C2, C3), the plurality of core wire support members (31) each having a hole (31A) through which the silicon core wire (C1, C2, C3) is to pass; and a position change mechanism (40) for changing a relative position where the silicon core wire (C1, C2, C3) passes through in relation to the hole (31A).