A joint structure joins an electronic element 12 included in an electronic component to an electrode 14 included in that electronic component. The joint structure includes a solder layer, which contains 0.2 to 6% by weight of copper, 0.02 to 0.2% by weight of germanium and 93.8 to 99.78% by weight of bismuth, a nickel layer provided between the solder layer and the electrode, and a barrier layer provided between the nickel layer and the solder layer. Here, the barrier layer is formed so as to have an average thickness of from 0.5 to 4.5 μm after the electronic element and the electrode are joined by the solder layer.