To provide a draft chamber which is used for chemical experiments, has a baffle panel on the back surface thereof to form an exhaust route for discharging a harmful gas etc. and is constituted so that the flow velocity of an air current in an opening is uniformized to prevent a backward flow from being produced from a working chamber and a turbulent flow from being produced in the working chamber.

The baffle panel, which is arranged on the back surface of the draft chamber to form the exhaust route, is formed from three panels, namely, an upper panel, a middle panel and a lower panel. A space is arranged between the ceiling of the draft chamber and the upper panel, between the upper panel and the middle panel, between the middle panel and the lower panel and between the lower panel and a working table of the draft chamber so that air flows in or out of the exhaust route through the arranged spaces. Furthermore, a space is arranged between the baffle panel and each of the sidewall faces of the draft chamber so that air also flows in or out of the exhaust route through the arranged spaces. As a result, the flow velocity of the air current in the opening of the draft chamber can be uniformized. The flow velocity is uniformized much more by further arranging an opening in the middle of the baffle panel.