A solder which can form a soldered joint of good bonding strength on a Ni layer containing a small amount of P formed from electroless Ni plating with a P-containing plating solution comprises 60 64 mass % of Sn, 0.002 0.01 mass % of P, 0.04 0.3 mass % of Cu, and a remainder of Pb. The solder is particularly suitable for forming a solder bump on a Cu electrode which has been coated with Ni by electroless plating.