We have devised a suspended ceiling with an oblique member, which is a C-section steel changed to a square steel pipe, for the ceiling foundation. In order to confirm the earthquake resistance of the devised ceiling foundation, a ceiling unit test was conducted. As a result, the following was found. For specimens with suspension lengths of 0.5m, 1.0m, and 1.5m, the earthquake resistance decreases as the suspension length increases.
