Provided are a tin-containing alloy plating bath being capable of manufacturing a tin-containing alloy plated product suitable for electric and electronic members with excellent anti-oxidation performance, and an electroplating method using the bath. This is achieved by generating the values of the attributes by a CoS logic at the time of or immediately prior to the time the entry is transmitted to an application, rather than storing the values of the attributes with the attribute itself. Comparing a feature amount obtained from the estimated contour and a feature amount of the area of the target object, the temporarily setting is reset by determining that the value for the temporary setting is not appropriate when the degree of matching of the both is smaller than a reference value. However, the use of the main expansion valve in series with these restrictions ensures that each of the restrictions can be relatively simple items.