A permanent part attachment portion and an additional part attachment portion are provided to a case. A terminal portion of a permanent bus bar is disposed in the permanent part attachment portion, and a terminal portion of an additional bus bar is disposed in the additional part attachment portion by allowing the additional bus bar to be contained in the case in a removable manner. It thus becomes possible to provide an electrical connection box that is adaptable to an addition of an electrical part without changing a die used to mold the case and/or a die used to form the bus bars.