PROBLEM TO BE SOLVED: To provide a sterile work equipment free from troubles of intrusion of outer atmosphere into a work chamber 4 and flow out of atmosphere in the work chamber 4 to the outer atmosphere.SOLUTION: The work chamber 4 isolated from outer atmosphere is connected with a hydrogen peroxide vapor feeding means 54 to sterilize the space in the work chamber 4 by feeding hydrogen peroxide vapor to the chamber, and a blower 34 to keep the space in the work chamber 4 to positive pressure by sending air into the chamber. The work chamber 4 is provided with a communication chamber 12 communicating with the work chamber 4 through an inlet opening 6, and the communication chamber 12 is provided with an outer opening 16 communicating with the outer atmosphere. The communication chamber 12 is divided into three sections 12A, 12B and 12C with two dividing walls 18, 20 having communication openings 22, 24. An exhaustion means 72 is attached to the section 12A communicating with the outer atmosphere through the outer opening 16 among these three sections 12A, 12B and 12C, and the pressure in the communication chamber 12 is gradually lowered from the section 12C at the side of the work chamber 4 toward the section 12A at the outer side.
