There are provided an adhesive for connecting a circuit to be interposed between substrates having circuit electrodes thereon opposed to each other and to electrically connect the circuit electrodes on the substrates opposed to each other to the pressurizing direction under pressure, wherein the adhesive contains a compound having an acid equivalent of 5 to 500 KOH mg/g, and an adhesive for connecting a circuit to be interposed between substrates having circuit electrodes opposed to each other and to electrically connect the electrodes on the substrate opposed to each other to the pressurizing direction under pressure, wherein the adhesive comprises a first adhesive layer and a second adhesive layer, and a glass transition temperature of the first adhesive layer after pressure connection is higher than the glass transition temperature of the second adhesive layer after pressure connection.