Provided is an insertion aid for assisting in insertion of an insertion member having a rigid distal end part into a paranasal sinus or an opening leading to the paranasal sinus. The insertion aid includes a guiding portion having an elongated and curved one end part and configured to guide an insertion route of the insertion member, a guided portion configured to hold the insertion member and movable along the guiding portion, and a support portion supporting the other end part of the guiding portion.
