Field measurements and questionnaire survey in a new office building which was daylit from light well were conducted. It was found that the deeper the target on the surface of the light well, the larger the interreflection on the surface of the light well. From the results of the questionnaire survey, it was found that the occupants requested spaciousness, daylighting and weather information for the light well. It was identified that the larger the configuration factor of the light well, the stronger the occupants sensed the effects of daylight from the light well. About 60 % of the occupants judged the light environment in the office space comfortable whether they sensed daylight or not.