To provide tin or tin alloy which achieves prevention of generation of soft errors caused by influence of α rays emitted from a material particularly a solder material in the vicinity of a semiconductor chip, in a highly densified semiconductor device of high capacity, and to provide a method for producing the tin or the tin alloy.

There is provided the tin whose sample after melting and casting has an α dose of less than 0.0005 cph/cm². It is preferable that : each α dose is less than 0.0005 cph/cm2 1 week, 3 weeks, 1 month, 2 months, 6 months and 30 months after melting and casting; an α dose measured at first time of sample is less than 0.0002 cph/cm2, and difference between the α dose and an α dose measured at 5 months later is less than 0.0003 cph/cm2. The tin alloy has a Pb content of 0.1 ppm or less, a content of each U and Th of 5 ppb or less, and contains tin of 40% or more. A raw material tin having purity of 3 N level is exuded with hydrochloric acid or sulfuric acid and then subjected to electrolytic refining by using a specified electrolytic solution.