to provide a structure capable of securing satisfactory induction coupling efficiency and high reliability in manufacturing an induction coupling apparatus used in power line carrier communication , the induction coupling apparatus having a magnetic core formed from a first core element part and a second core element part so that a gap would be formed between the core element parts , includes : a core parallel moving mechanism for carrying out relative and parallel movement of the first core element part and the second core element part in a direction that the length of the gap varies ; and a predetermined gap length regulating member for limiting parallel movement in a direction that the first core element part and the second core element part approach each other to regulate the gap length to the predetermined gap length in the case that the core parallel moving mechanism is used for the parallel movement .