The present invention is to provide a label automatic application device and a label automatic application method capable of easily removing a large number of single labels one by one from a label band body formed by coupling the single labels while displacing and overlapping the labels with each other in the longitudinal direction, so as to automatically apply a large amount of labels to application bodies per unit time.A label band body 8 formed by displacing a little and overlapping many single labels with each other is attached to a label transfer belt conveyor 32. The label transfer belt conveyor 32 to which the label band body 8 is attached and a product transfer belt conveyor 52 for moving application bodies 54 are arranged so that the forward directions thereof are the opposite directions to each other. The air is jetted by an air jet means 38 to a surface onto which a bonding means 5 is coated in a front end 1y of a lead label 1a of the label band body 8. The surface onto which the bonding means 5 is coated in the front end 1y of the lead label 1a is warped in the inversion direction and rolled up outward, so that the application body 54 easily comes into contact with the bonding means 5 of the front end 1y.