PURPOSE: To comply an image drawing speed to a writing liquid supply by connecting the upper end of a writing fluid chamber of a specified construction to a writing fluid storage chamber whose volume is reduced in accordance with fluid consumption through a shutoff fitment which is opened/closed in relation to the upper and lower limits of a filled writing fluid level and making the lower end of the chamber communicate with a writing tip.

CONSTITUTION: A tubular shaft part 3 is provided which has a writing tube piece 1 and a tubular shaft part 3 having a forward end member 2, consisting of a cleaning wire 5 fixed to a weight member 4 which reciprocates to some extent in the axial direction, on the front end. In addition, a writing fluid chamber 9 is provided which is structured of a writing fluid storage chamber 7 whose volume is reduced in accordance with the consumption of a writing fluid and a flexible non-elastic material with at least one wall, in the tubular shaft part 3. The lower end of the writing fluid chamber 9 communicates with the forward end member 2 and the upper end communicates with the writing fluid storage chamber 7 through a solenoid valve 12 which opens when a filled writing fluid level reaches the lower level and closes when the filled writing fluid level reaches the upper level respectively.