A confidential sheet in the form of a sealed letter, postcard or the like and having a sheet body bearing the information to be concealed on one surface thereof, the confidential sheet being formed in a lapped state by folding the sheet body in at least two with the information bearing surface inside, said sheet body comprises front and back sheets, with a nontransparent sheet interposed and permanently secured therebetween for preventing the information on the inner surface from being seen through from outside, and said front and back sheets are formed of paper.