Scene Transition Nets(STN) is a very useful modeling method for discrete-continuous hybrid systems. However, it is difficult to write STN in standard object-oriented programming languages because STN programming requires much skill of object-oriented programming and high knowledge of STN of designers. To overcome this problem, the authors have developed a useful GUI simulator software for modeling and simulations of STN. The experimental results of a transport system including an AGV showed the availability of our software.