Abstract: Guillotine shearing machine, especially for cutting continuous metal bands (90) in which each of the two longitudinal blades (15), (16) counterposed by means of connections to connecting rods (39), (40), (41), (42) each supported by a pair of cranks (31-32), (35-36) and (33-34), (37-38), translates, both parallel to each other, on equal circular trajectories in such a way that one blade (15) encountering the other (16) in proximity to the cutting plane and progressively superimposing each other, effects the cut, speed of the blades (15), (16) in each cycle being regulated according to the sliding speed of the band (90) so that in the zone of contact the speed of the blades (15), (16) coincides with that of the band (90) enabling pieces of band to be cut off in whatever length is desired.