Paper which exhibits more favorable forgery prevention effect is provided. Paper contains first and second surface regions opposed to each other and an intermediate region interposed between the first and second surface regions. Each of the first and second surface regions and the intermediate region contains cellulose fibers. At least the first surface region further comprises functional fibers which, upon reception of a physical stimulus, make a response different from that made by the cellulose fibers to the physical stimulus. The functional fibers contained in the first surface region are mingled with the cellulose fibers in the first surface region and are oriented in one direction which is parallel or oblique to one main surface of the paper.