There is provided a format processing method for overlaying data of a file located on an Internet server onto a predetermined field in a form. In particular, there is provided a form processing method for reading a field data file storing data to be overlaid onto a defined field in a form, and overlaying data of the field data file onto a field in the form, the form processing method including: a determination step of determining, if data of the field data file is description specifying an external file, whether the description of the data is in a URL format (step S301); an overlaying step of downloading the external file in a network server in compliance with Internet protocols (step S305) and overlaying the data of the downloaded external file onto the field in the form if the description is determined to be in a URL format at the determination step (step S301).