An insertion aid (21) according to the present invention assists in insertion of an insertion member (20) having a rigid distal end part into a paranasal sinus or an opening leading to the paranasal sinus, and includes: a guiding portion (211) having an elongated and curved one end part and configured to guide an insertion route of the insertion member(20) a guided portion (213) including a holding part for holding the insertion member(20) and including a moving part continuous to the holding part and movable along the guiding portion (211) and a support portion (212) for supporting the other end part of the guiding portion (211).
