An ink jet printing head is attachable to/detachable from an ink jet printing apparatus and includes an electric wiring member formed of a TAB tape to which terminals are provided, and has a wiring exposed through an end section of the electric wiring member, the terminals accepting signals by making contact with a connection portion on the part of the apparatus when the head is attached to the apparatus. An opening is provided in a supporting member which supports the electric wiring member, the opening extending in a direction traversing an area where the electric wiring member is supported. Thereby, movement of liquid, such as water and ink, to the end section is blocked, the liquid moving through a gap between a back surface of the electric wiring member and a surface of the supporting member.