The formation of microlayer beneath boiling bubbles during nucleate pool boiling has been confirmed by many researchers. The vigorous evaporation of the microlayer plays an important role in boiling heat transfer, because of the high thermal conductance of the micron-order thickness of liquid film. However, the experimental knowledge on the microlayer evaporation has been limited owing to the difficulty of measuring the evaporation. In this study, the laser interferometric method was adopted to investigate the microlayer structure during the nucleate pool boiling for ethanol. The microlayer evaporation was determined from the variation of microlayer volume. As a result, it was confirmed that micro layer evaporation contributes significantly to total evaporation, and that its contribution ratio coincided with the previous results. (C) 2018 Elsevier Ltd. All rights reserved.