In steel-framed buildings, the necessary fireproof coating is applied against an expected fire. There are many types of fireproof coatings, but in many cases sprayed rock wool is used. In recent years, many ceiling-less spaces have appeared in restaurants and the like, but in many cases, paint is applied on the spray rock wool from the viewpoint of design. Therefore, in this study, a material test was conducted to understand the effect of the paint applied on the sprayed rock wool of the fireproof coating on the fireproof performance.