To provide a local exhauster for detecting the generation of malodor, noxious gas, smoke, high temperature, flame, and the like of a laboratory to strengthen the security, environmental conservation, abnormality alarm, and the like of a user.

A malodor and noxious gas sensor 2, a temperature sensor 5, a smoke sensor 3 and a flame sensor 4 are provided in a treatment chamber 1a in a draft chamber body 1, and a control part 6 detects an output signal from each sensor. A danger signal value of each sensor is set to an upper limit value 100%, and a maximum % output signal is selected out of the % output signal of each sensor at real time. Corresponding to the maximum % output signal, the control part 6 controls an inverter 7 to control the rotating speed of an exhaust fan, thus changing an exhaust air quantity to appropriate quantity. When the maximum % output signal becomes a prescribed set value or more, an abnormality lamp of an alarm display part 12a is lighted to emit an alarm sound, and abnormality contents are displayed.