A guidewire insertion aid (11) according to the present invention is used for feeding out a guidewire (1) inserted in a housing (2) in order to insert said guidewire into the lumen of a piece of medical equipment. The insertion aid (11) comprises: a main body (21), a housing support part (22) and a guidewire support part (26). A sliding contact part (28) is disposed between the housing support part (22) and the guidewire support part (26). The sliding contact part (28) extends in the lengthwise direction of the main body and has a sliding contact surface (28) for the guidewire (1). A feed-out member (51) is provided on the main body (21) and has a water-retentive water-retention member (52). The feed-out member (51) is disposed with the water-retention member (52) side thereof facing towards the sliding contact surface (29). The feed-out member (51) can be displaced while the guidewire (1) is held between said feed-out member and the sliding contact part (28).
