the invention relates to a tobacco content control device for use in a cigarette manufacturing machine , wherein shredded tobacco is fed by means of a hole - provided cigarette conveyor , is trimmed by a trimming means for regulating the amount of the shredded tobacco , and is then wrapped by a wrapping means , thereby producing stick - like cigarettes . the control device comprises a fist radiometric density detector for detecting the density of the shredded tobacco before the tobacco content is trimmed , a second radiometric density detector for detecting the density of the stick - like cigarettes , a feed forward control circuit , and a feed back control circuit . the feed forward control circuit includes a high pass filter for picking up only high - frequency components out of a first signal supplied from the first radiometric density detector , and a delay circuit for delaying the high - frequency components by a predetermined time . by use of these structural elements , the feed forward control circuit generates a feed forward control signal corresponding to an instantaneous variation in the first signal . the feed back control circuit includes an integrator for integrating a second signal supplied from the second radiometric density detector . by use of this structural element , the feed back control circuit generates a feed back control signal corresponding to an average variation in the second signal . the feed forward control signal and the feed back control signal are added together , on the basis of which the trimming means is controlled .