Evolvable hardware adjusts oneself to changeable environments by self-organizing the circuit. Due to its high productivity and creativity for designing circuit, it is widely investigated. However, it is ver) difficult to appl) it to a complicated circuit, because the search space increases exponentially as the complexity of hardware. In this paper, we propose a modular approach to evolving complex hardware circuits effectivel?. A comparative experiment with the conventional evolutionar) approach indicates that the proposed method works 50-1000 times faster and yields a more optimized hardware.