For this study, a Dismantling Planning Support System (DPSS) based on Augmented Reality technology was developed. Its effectiveness and applicability to a real working field were evaluated using a subjective experiment. The DPSS operators can simulate how to locate scaffolding and temporary enclosures (greenhouses) in a real dismantling field in order to decide their layout and to predict the amounts of necessary parts. An interview and questionnaire survey were conducted with Fugen Decommissioning Engineering Center (DEC) staff and a human interface expert, who used DPSS along with a scenario in which scaffolding and greenhouses were located in a turbine cooling water room of Fugen DEC. The experimental results show that the operation for locating the virtual scaffolding and greenhouses using marker boards is intuitive and comprehensive. However, additional research needs to be undertaken in order to improve the DPSS, particularly with respect to its graphical user interface.