PURPOSE: To make it possible to excellently maintain working environments within a working chamber by dividing a breeding chamber into a working chamber and a breeding chamber using a curtain, providing first air conditioning means communicating with the external in the working chamber, and air-conditioning the breeding chamber by means of a circulation pipe through strong deodoring and dedusting means.

CONSTITUTION: External air OA enters a first air-conditioning unit 6 through an air intake port to practise adjustment of temperature and humidity by adjusting means 6a, 6b, 6c, 6d, 6e and 6f, and then is introduced into a working chamber 1a by means of a blower 6g. While the air within the working chamber 1a passes through an exhaust pipe 7 and is discharged as shown by arrow B as exhaust air EXA, air is deodored in a deodoring filter 16 in the intermediate thereof, on one hand, and air within the breeding chamber 1b is passed through a circulation pipe 15 by a circulation blower 16g, and adjustment of temperature and humidity and dedusting of air is carried out by respective adjusting means of the second air conditioning unit 16. Since the working chamber 1a and the breeding chamber 1b are partitioned by a curtain 10, dusts such as furs and odor within the breeding chamber 1b hardly make ingress into the working chamber 1a, thus solving the problem of allergy to animal.