To provide a writing utensil, with a properly modified surface to an ink applied, which is equipped with an ink felt and an ink, with such advantages that a processed film is uniformly thin although it undergoes a simplified process without passing through a dangerous process such as a chromate intermixing treatment, the wetting properties to the ink are satisfactory, the ink retaining force is excellent even in case an ink tank receives a pressure change, no ink dripping and abnormal intake occur, the writing follow-up properties of the ink are good, and especially a well-balanced remedy for solving inherent problems from the viewpoint of compatibility of the simplification of a pen felt surface modification process with a surface modification performance, can be proposed.

This writing utensil has at least, the pen felt, ink tank and ink to be packed in the ink tank. In addition, the writing utensil uses the pen felt with its surface modified in a special way so that a specific contact angle with the ink to be used can be formed.