Measuring the thermal conductivity of a high performance thermal insulation material within a short time is challenging. In the present study, a laser flash method is adopted to measure the thermal diffusivity of porous thermal insulation material. Small sample size and short measuring time are major advantages of this method. The specific heat capacity was measured by a differential scanning calorimeter (DSC). With known density, the thermal conductivity was obtained. Applying a calibration routine, the measured thermal conductivity of the porous material is only 0.039 W/(m K) at room temperature. This value is in good agreement with the data obtained using conventional method. It demonstrates that the laser flash method is a reliable technique to determine the performance of a very low thermal conductivity material. (C) 2016 The Society of Powder Technology Japan. Published by Elsevier B.V. and The Society of Powder Technology Japan. All rights reserved.