Wire holding device

electrical wire holding device includes a seal retention member having an insertion hole configured to allow an electrical wire to be inserted therethrough, and housed in a mounting hole formed in a mounted member, an outer periphery seal member retained on an outer peripheral surface of the seal retention member, and sealing a gap between an inner surface of the mounting hole and seal retention member, and an electrical wire holding member juxtaposed with the seal retention member along the electrical wire, and having a fixing part configured to retain the electrical wire and fixing the electrical wire to the mounted member. The seal retention member is configured to be relatively movable to the electrical wire holding member.