Wittgenstein´s Tractatus Logico-Philosophicus can be regarded as the first attempt to use the concept of possible world in the analysis of language. Since Wittgenstein does not use the expression possible world, the author of this paper draws attention to those parts of Tractatus that presuppose such concept. Then the author concentrates on the relation of Wittgenstein´s conception of possible world to the metaphysics of Tractatus. For Wittgenstein, the possible world is any combination of state of affairs. On the other hand, some combinations of states of affairs are by the metaphysics of Tractatus excluded as illogical. The same is true of all possible distributions of attributes to ordered sets of objects that constitute states of affairs. It seems that Wittgenstein did not recognize these difficulties.