An electronic device includes an electrode including Cu, a solder including Sn and provided above the electrode, and a joining layer including In and Ag and provided along a boundary between the electrode and the solder. The joining layer including In and Ag prevents Cu—Sn alloy, such as Cu6 Sn5, from being formed at the boundary between the electrode and the solder, and prevents generation of voids and cracks resulting from the Cu—Sn alloy. The electrode and the solder are joined with sufficient strength by the joining layer.