This paper proposes a damage assessment methodology for the non-structural elements, especially ceiling elements of a building, utilizing an inspection robot. The developed inspection robot equipped with a wireless camera and data processing function has a capability of providing valuable information for the repair and maintenance decision making of a damaged structure. The inspection robots will be able to estimate the damage condition without any process of engineers' on-site-inspection involved. The robots also can gather the static data of the nonstructural elements from the sensor, which are distributed on the nonstructural elements. To demonstrate the effectiveness of the inspection robot, the robot is utilized to estimate the ceiling of a real structure damaged by the 2011 off the Pacific coast of Tohoku Earthquake. And conceptual experiment is also conducted for the purpose of evaluating the proposed damage assessment methodology in cooperation with the smart sensor and the inspection robot. The proposed methodology will provide useful information to the maintenance and repair planning of a damaged structure.