A mounting structure includes a BGA including a BGA electrode, a circuit board including a circuit board electrode, and a solder joining portion which is arranged on the circuit board electrode and is connected to the BGA electrode. The solder joining portion is formed of Cu having a content ratio in a range from 0.6 mass % to 1.2 mass %, inclusive, Ag having a content ratio in a range from 3.0 mass % to 4.0 mass %, inclusive, Bi having a content ratio in a range from 0 mass % to 1.0 mass %, inclusive, In, and Sn. A range of the content ratio of In is different according to the content ratio of Cu.