A pen including an ink reservoir to store an ink; a pen tip which has a proximal end and a distal end opposite to the proximal end and applies an ink to a coating target; an ink guide to guide the ink in the reservoir toward the pen tip; and a holder part which has a through hole through which the pen tip is inserted and holds at least the proximal end of the pen tip while exposing the distal end of the pen tip with the pen tip inserted through the through hole. The holder part includes: an ink holding part capable of holding the ink from the ink guide and formed at least partially around a circumference of the through hole; and a first opening opening on an inner circumferential surface that defines the through hole and communicating with the ink holding part.