Thermal conductivity of ALC panels is described as 0.19 W/(m・K) in JIS A 5416_2016 which is used for a standard value for JIS certification. On the other hand, 0.17 W/(m・K) is generally used for the design value of ALC panels. In this paper, the design value is examined by measurements of actual ALC under various conditions. The results show that the value is appropriate to use to designing.