The purpose of this study was to evaluate comfort in a classroom. The questionnaire was given to 120 university students in the classroom. On the basis of previous studies, the evaluating factors on comfort in a classroom were selected and they were lightness, glareness, air freshness, dust, odor, loudness, distracting sounds, humidity and temperature. The scale of them was used five voting scales. The results showed that the lightness was the most important one among the evaluating factors because a classroom is an environment to have to see many things.