The aim of this paper is to show how big model checking problems for Computation Tree Logic (CTL) can be handled by using current powerful vector processors. Although efficient recursive model checking algorithms for CTL, which run in time proportional to both the size of Kripke structures and the length of formulas, have been already proposed [7, 2], their algorithms cannot be vectorized due to recursive procedure calls. In this paper we propose a new model checking algorithm, called a vectorized model checking algorithm, for CTL which is suitable for the execution on vector processors. It can handle more than 1 million state Kripke structure derived from a deterministic sequential machine.