A filling system for a fountain pen includes a pump unit, an air channel connected to the pump unit and to a first connection for connecting to the fountain pen, and an ink channel separate from the air channel and having an immersion end for immersing in ink and which is connected to a second connection for connecting to the fountain pen. The pump unit is designed to introduce a specified air volume into the air channel with positive pressure in order to flush ink out of the fountain pen and subsequently apply a negative pressure to the air channel such that a specified ink volume is suctioned out of the ink channel into the fountain pen.