This disclosure relates to a technique for automatically selecting compression/non-compression for each digital document upon archiving digital documents. Whether or not each digital document is to be stored in a compressed or non-compressed state is determined based on a predetermined reference. A digital document which is determined to be stored in a compressed state is controlled to be stored in the compressed state, and a digital document which is determined to be stored in a non-compressed state is controlled to be stored in the non-compressed state, thus generating an archive file. This disclosure relates to a technique for determining whether or not each digital document is to be uploaded to a server, and generating an archive file that stores abstract data of uploaded digital documents, and digital documents which are not uploaded, upon archiving digital documents.