Confirmation Sampling, introduced by Christiani, Pagh and Thorup, is a simple randomized algorithm to find the smallest element of an array. Compared to Simple Sampling, Confirmation Sampling does not need any probabilities of elements in the probability distribution and has higher accuracy. This report shows the proof of the correctness of Confirmation Sampling, some special cases in Confirmation Sampling as well as the results, and the evaluation and comparison of Confirmation Sampling and Simple Sampling.