Abstract: Female and male terminals are provided on body casings of opposite ones of an electric connection box and an electronic unit so as to be electrically connected when combined together. The electric connection box and the electronic unit are connected together through hinge means, provided respectively on the two body casings, so as to be pivotally moved relative to each other in a combining direction, the two hinge means being formed by a pivot grooves and a pivot rods, respectively. The two hinge means, formed respectively by the pivot grooves and the pivot rod, can be engaged with and disengaged from each other with a one-touch operation. With this construction, any deflection will not occur in a positioning operation when combining the electronic unit with the electric connection box and therefore the male terminals can be positively fittingly connected to the female terminals, respectively, thus avoiding a half-fitted condition.