To provide a lithographic plate causing little residual film by cutting, and to provide a device and a method of cutting a strip plate for the lithographic plate capable of reducing the residual film generated by cutting.

Shape of an upper blade 50 positioned at an image forming surface 12U side is decided so that a contact angle between a contact surface 50S and the image forming surface 12U becomes 10-60 degree. A range of the pressure working to an aluminum web 12 is narrowed by setting the contact angle θ to 10 degree or more, and a residual film generation range becomes narrow, and the unnecessary ink to be adhered to a blanket when printing is reduced.