Restoration work following a sediment disaster or volcano disaster may be executed in extremely dangerous places. Construction in such dangerous places can be executed safely if it can be done using construction equipment that can be operated remotely while observing camera images. Construction using such remote control type construction machinery is called 'unmanned construction', and it has been carried out more than 150 sites in disaster prone Japan. From the experience in the construction site so far, it is said that construction efficiency of unmanned construction is about 50% compared to normal construction, so it is necessary to improve its construction efficiency in order to enhance the productivity of restoration work. In order to improve construction efficiency using unmanned construction, we think that it will be necessary to organize the information that each operator needs and reflect this organization in the interface. In this study the operators' lines of sight during remote operation was measured in an effort to clarify the relationship between construction efficiency and line of sight. As a result, in order to clarify the situation around the excavator, it was found that only the information from inside camera is insufficient and that from the outside camera is also necessary. And also it was found that operators must have the ability to effectively use multiple images obtained by inside and outside cameras.