Abstract: A holding device for a highlighter pen, comprising a holding case and a base. The holding case includes: a channel configured to receive the highlighter pen and having a first opening and a second; a gripping unit in the channel, configured to removably grip the highlighter pen; a chamber extending from the second end of the channel and configured to receive a tip of the highlighter pen, the chamber comprising a sealing unit configured to cooperate with the highlighter pen when the highlighter pen has traversed the sealing unit, to generate an airtight environment in which the tip of the highlighter pen is contained; at least one first magnet. The base has at least one second magnet, such that attraction between the at least one first magnet and the at least one second magnet makes the base removably joinable to the holding case.