To provide a simple molding machine of a cylindrical paper container suitable for inexpensively manufacturing a trially made product or a small lot of cylindrical paper containers without requiring a large installation space at the time of manufacture of the cylindrical paper container, and its molding method.

The simple molding machine 100 of the cylindrical paper container comprises a means for inserting a sack bonded body member in a body former 50 divided into two parts, a means for forming the body member into a cylindrical shape, a means for applying a hot melt type adhesive to the upper end of the inner surface of the cylindrical body part, a means for moving the body former 50 and a turntable 60 under a lid molding female mold 40 on which a bottom member is placed and lowering the lid molding male mold 44 positioned above the female mold 40 to insert the bottom member placed on the female mold in the cylindrical body part while molding the bottom member into a circular tray shape to fit and bond the same to the cylindrical body part and a means for raising the lid molding male mold 44 and opening the body former 50 to eject the cylindrical paper container.