In order to give a new insight to fundamental problems of quantum mechanics, relativity and mind, we propose a world model suggested from the monadology of Leibniz. The world is assumed to consist of monads which have their individuality and whose primary attribute is a space-time frame and not a position in spacetime. Each monad has freedom to change its frame. Accompanying this change, the world time is put forward, and the world state jumps off the unitary evolution. This model explains not only the measurement process of quantum mechanics but also the passing now and the origin of free will.