We conducted experiment to determine the optimal thermal environment for elderly concerning the air velocity in the summer. To determine their comfortable thermal environment the male subjects of youth and elder controlled the air velocity so that they feel thermal environment comfortable. We measured their physiological and psychological responses and compared the results with the past experiments which were done with young and elderly female subjects. We carried out experiments in a climate chamber testing simultaneously two subjects. We set up two fan apparatus which were able to regulate the air velocity. The air temperatures were set at 28, 30, 32℃ for the elderly and 26, 28, 30℃ for the young subjects. The mean radiant temperature was equal to the air temperature. The subjects sat on a chair during the experiments in summer clothes (0.4clo). The subjects regulated the air velocities at will so as to feel comfortable at any time. The number of subjects were 10 active elderly and 8 healthy young men. The main results were as follows: 1) The mean skin temperature became higher as the air temperature rose. In the same air temperature, mean skin temperature of the elderly male was lower than of the young male in 0.3〜0.6℃. 2) Before being exposed to air movement, the higher the air temperature became, the higher the thermal sensation vote. The thermal sensation vote after the exposure of the air movement became cooler by the air movement. But the elderly male's reports differed according to the air temperature. 3) Like the young male, the elderly male didn't change the air velocities so that heat flow rate at the forehead and the thermal sensation vote became the same level. It shows that the elderly's physiological function declined and thermal sensation became more insensible. 4) The average of the preferred air velocities at each air temperature were 0.41m/s at 28℃, 0.80m/s 30℃ and 1.08m/s at 32℃ for the elderly male, and 0.46m/s at 26℃, 0.84m/s at 28℃, and 1.37m/s at 30℃ for the young male. In each air temperature the elderly preferred slower air movement than the young, and as the air temperature rose by 2℃ the air velocities became faster by 0.4〜0.5m/s in each age group. 5) Compared with the elderly female's preferred air velocities of the elderly male were slower. It is considered that daily living customs or consciousnesses influence to the preferred air velocities.