A method of manufacturing an insulating sheet, a method of manufacturing a copper clad laminate, and a method of manufacturing a printed circuit board, as well as a printed circuit board manufactured using these methods are disclosed. The method of manufacturing an insulating sheet can include: forming a thermoplastic reinforcement material, which includes fibers secured by a thermoplastic polymer binder, and in which pores are formed; forming a thermoplastic resin layer such that the thermoplastic reinforcement material is impregnated with a thermoplastic resin; and hot pressing the thermoplastic reinforcement material and the thermoplastic resin layer. This method can be utilized to manufacture an insulating sheet, which has a low rate of moisture absorption and superb electrical properties, including a low dielectric constant (Dk) and low dielectric loss (Df), and in which the fibers can readily be impregnated with the resin.