A silver and silver 
alloy plating bath, includes (A) a soluble salt, having a silver salt or a mixture of a silver salt and a salt of a 
metal such as 
tin, 
bismuth, 
indium, lead, and the like; and (B) a particular aliphatic 
sulfide compound, such as thiobis(diethyleneglycol), dithiobis(triglycerol), 3,3′-thiodipropanol, thiodiglycerin, 3,6-dithiooctane-1,8-
diol, and the like, which contain at least one or more of an 
ether oxygen atom, a 1-hydroxypropyl group, a hydroxypropylene group, or two or more of a 
sulfide bond in the molecule, and not containing a basic 
nitrogen atom. Compared to baths containing aliphatic monosulfide compounds, such as 
thiodiglycol or beta-
thiodiglycol, which do not contain an 
ether oxygen atom, 1-hydroxypropyl group, a hydroxypropylene group, or two or more of a 
sulfide bond in the molecule, by having these particular compounds, the plating bath of the present invention has excellent stability over 
extended time, excellent co-deposition of silver and various metals, and excellent appearance of the electrodeposition 
coating.