An ink jet head for ejecting ink, has an ink ejecting portion having an ink ejecting port formed thereon so as to eject ink through the ink ejecting port, a positioning portion for definitely determining the position of the ink jet head relative to an apparatus using the ink jet head when the ink jet head is fitted to the apparatus, an ink supplying portion adapted to be connected an ink supplying unit while ink is supplied to the ink jet head, and an electric connecting portion adapted to be electrically connected to an electric connecting portion on the apparatus side so as to send and receive signals. The positioning portion, the ink supplying portion and the electric connecting portion are disposed on a different surface from a surface on which the ink ejecting portion is disposed and at least one of the electric portion and the ink supplying portion is disposed on an opposite side surface to a surface on which the positioning portion is disposed.