An ink printer designed to make users free from any danger when an inktank is replaced and to prevent ink from leaking out when the inktank is detached. The joint part of an inktank is pressed against the ink guide of a print head to couple the inktank and the print head together, so that ink is supplied from the inktank to the print head. The joint part is supplied with a porous material. When the inktank is attached, the porous material is compressed and contained in the joint part. When the inktank is detached from the print head, the volume of the porous material increases thereby raising its porosity. The ink remaining in the joint part is absorbed by the porous material whose porosity has been raised, so that ink is prevented from flowing out in the vicinity of the joint part when the inktank is removed.