An electroless gold plating bath includes a water-soluble gold compound, a completing agent, an aldehyde compound, and an amine compound represented by R1—NH—C2H4—NH—R2 or (CH2—NH—C2H4—NH—CH2)n—R4 (wherein R1 to R4 represent —OH, —CH3, —CH2OH, —C2H4OH, —CH2N(CH3)2, —CH2NH(CH2OH), CH2NH(C2H4OH), —C2H4NH(CH2OH), —C2H4NH(C2H4OH), —CH2N(CH2OH)2, —CH2N(C2H4OH)2, —C2H4N(CH2OH)2 or —C2H4N(C2H4OH)2, and n is an integer of 1 to 4).
The electroless gold plating can be carried out without corrosion of an underlying metal to be plated at a stable deposition rate. Because of the high deposition rate and the immersion and reduction types, thickening of a plated coating is possible in one solution and the color of the coating is not degraded to provide a good appearance while keeping a lemon yellow color inherent to gold.