In recent years, security has become a major concern in ad hoc network technology. It has unique characteristics that make new challenges arise compared to its wired networks or traditional wireless networks counterpart. Due to these unique characteristics, the traditional intrusion detection techniques for wired networks and wireless networks are not well suited for ad hoc networks. In this paper, we propose a Manager-based architecture for intrusion detection system to shorten an intrusion detection time in an ad hoc network environment. We have evaluated the performance of proposed system through simulation-based experiment and compared it with other existing methods. The result shows that our method gives the better performance.