An ink tank is removably mountable to an ink jet head body having a discharge opening for discharging ink, an ink communication pipe for introducing ink to an ink jet head, and a first coupling member. The ink tank comprises a container body for storing ink to be supplied to the ink jet head, an absorbent member disposed in the container body for holding ink, and an ink supply port into which the ink communication pipe is inserted when the ink tank is connected with the ink jet head body. The ink tank includes a first engagement member to connect and engage with the coupling member when the ink tank is connected with the ink jet head body and a second engagement member to contact and engage a part of the ink jet head body when the ink tank is connected with the ink jet head body.