To provide a waste treatment device capable of improving operational efficiency by reducing the clogging of a dust removing filter.

The waste treatment device has an agitation means 5 for agitating a mixture containing thrown-in waste and a base material, a treatment vessel 10 for storing and decomposing the waste, an exhaust means 15 for exhausting air inside the treatment vessel 10 to the outside, a dust removing filter 24 for cleaning the exhaust and a control part for controlling the agitation means 5 and the exhaust means 15 in an operation mode for controlling operation of the agitation means 5 works with the exhaust means 15 in interlock with each other. The control part can perform the operation control of the agitation means 5 and the exhaust means 15 in such an operation mode that starts operating the exhaust means 15 after a lapse of a previously set time after the shutdown of the agitation means 15.