Problem to be solved. To solve the problem that, since inkjet printing on a cylindrical object side face is not easy, and printing on a conical object side face cannot be performed accurately, and a device is complicated and expensive, printing on a cylindrical/conical object side face is performed before being formed three-dimensionally. Solution. There are provided inexpensive method and device with a simple structure for printing on a cylindrical/conical object side face. A line head having two nozzle rows is arranged by using an L-shaped angle plate, to thereby facilitate parallel installation of the line head to the cylindrical/conical object side face, and to enable device switching for a cylindrical/conical object printing purpose by adjustment of one part component.