These exercises are intended to assist students in understandind the elements of set theory. The arrangement of topics follows the development found in Paul Halmos´Naïve Set Theory, although a student studying some other textbook should find the problems useful. The exercises are, on the whole, routine explorations of the definitions and theorems of set theory and are not puzzle or contest problems. The problems vary somewhat in difficulty, but nearly all should yield to the average student, provided he is endowed also with persistence. It is the author´s belief that maximal benefit will accrue to the student who does not look at the answers before he himself has some solution to check.