A mobile ad hoc network is an autonomous wireless network which consists of mobile nodes without any base stations. Many routing schemes and services have been proposed for mobile ad hoc networks. However, since these schemes tend to be evaluated through simulation experiments, it is not known whether they work effectively in real environments or not. Therefore, in order to verify their practical use in mobile ad hoc networks, it is necessary to perform field experiments using actual mobile nodes. If the network size is large, it is difficult to perform field experiments due to problems with limited battery, difficulty of topology control and so on. Realization of rapid topology change of the ad hoc networks topology is especially difficult. In order to solve this problem, this paper proposes a testing environment for mobile ad hoc network software, which emulates field experiments in wired networks.