Abstract: Device to automatically cut the slubbing, or spinning sliver, (11) of a yarn being worked, the device being used in any textile machine whatsoever and comprising a cutting assembly and sensor means (18) functionally associated with the cutting assembly, the sensor means (18) being suitable to detect the presence or absence of the yarn (11a) downstream of the draft and to activate the cutting assembly at least when they do not detect the presence of the yarn (11a), the cutting assembly comprising a support with which a blade is associated, the blade being movable with respect to the support to selectively assume an inactive position of non-interference with the slubbing (11) passing through or a cutting position in which it abuts against a contrasting element to cut the stubbing (11) transversely, the cutting assembly (17) comprising an electromagnet (21) and a magnetic element (35) suitable to cooperate with the movable blade (26) to keep it constrained to the core (21a) of the electromagnet (21) to assume th