According to a method for manufacturing a sheet-like heating element and a sheet-like heating element manufactured by the method of the present invention, cubics are pulverized into nanoparticles, the nanoparticle powder is mixed with carbon to become an original yarn, and the original yarn is cut to a length of between 0.2 mm and 0.8 mm and mixed into a pulp liquid to be formed into nanoparticle pulp. The sheet-like heating element forms a space where the particles can be rotated so as to allow 90% or higher far infrared radiation, and thus contributes to the health of users, entails a low defective rate since no bending occurs during the manufacturing, can be manufactured in quantity at low cost, and can be used for multiple purposes.