Connection method of the printed wiring board

The invention offers a board-connecting structure that can provide electrodes with a fine pitch and that can combine the insulating property and the connection reliability. The structure of connecting printed wiring boards 10 and 20 electrically connects a plurality of first electrodes 12 and 13 provided to be adjacent to each other on a first board 11 with a plurality of second electrodes 22 and 23 provided to be adjacent to each other on a second board 21 through an adhesive 30 that contains conductive particles 31 and that has anisotropic conductivity. By heating and pressing the adhesive placed between the mutually facing first electrode 12 and second electrode 22 and between the mutually facing first electrode 13 and second electrode 23, an adhesive layer 30a is formed between the first board 11 and the second board 21 and in the adhesive layer 30a, a cavity portion 33 is formed between the first electrodes 12 and 13 and between the second electrodes 22 and 23.