A connection member is provided that can be fabricated at low cost and easily attached to a target component. The connection member is a member to be connected to and to communicate with a first component. The connection member is further connectable to another connection member to be connected to and to communicate with a second component. The connection member includes a communicating portion connectable to and communicatable with the first component, engaging portions engageable into the other connection member, and engaged portions into which the other connection member is engageable. These connection members are mutually connectable to communicate with each other.