The invention intends to provide an electronic component mounting adhesive that can inhibit cracks and peelings in an electronic component mounting structure obtained by joining electronic components each other from occurring and an electronic component mounting structure obtained by joining electronic components with such an electronic component mounting adhesive. In an electronic component mounting structure, a first circuit board and a second circuit board are bonded with an electronic component mounting adhesive. Here, the electronic component mounting adhesive is obtained by dispersing metal particles having the melting temperature Mp lower than the glass transition temperature Tg of a cured material of a thermosetting resin in the thermosetting resin.