To provide a writing-erasing instrument set for the inscribing surface of a recording medium being rich in practicality, by which a clear hand writing without repelling can be formed on the inscribing surface of the recording medium such as a DVD, and in addition, re-writing at the same location by erasing the hand writing is possible when a miswriting happens, or when a listed item needs to be changed accompanying the change of a recorded content.

This writing-erasing instrument set for the inscribing surface of the recording medium consists of a marking pen for the inscribing surface of the recording medium, and an ink erasing utensil. In this case, the marking pen for the inscribing surface of the recording medium internally contains an ink composition consisting of at least a coloring agent, an alcohol with a carbon number of 4 or lower and/or a glycol ether based solvent with a carbon number of 6 or lower, a resin, a silicone based surfactant or a fluorine based surfactant. The ink erasing utensil houses an ink erasing liquid consisting of at least an alcohol with a carbon number of 4 or lower and/or a glycol ether based solvent with a carbon number of 6 or lower, a resin, a sulfate surfactant or a phosphate surfactant, a liquid compound selected from a fatty acid ester and an aliphatic hydrocarbon.