There is provided a surface treatment method for an electronic part, which uses a metal not containing lead and tin and having excellent solder wettability, is economical and has high reliability. In the surface treatment method for the electronic part in which a soldered part is subjected to a surface treatment of structure of three layers of nickel, palladium and gold, the palladium layer and the gold layer are formed by an electrolytic plating treatment, a thickness of the palladium layer is in a range of 0.007 to 0.1 .mu.m, a thickness of the gold layer is in a range of 0.003 to 0.02 .mu.m, and a relation of the thickness of the gold layer