The present invention provides a printing device optimizing information to be embedded by merging pieces of information of respective pages into a single piece of information in N-up printing. The printing device generates the information to be embedded according to a result of analyzing print parameters in print data when performing embedding printing processing of the information to be embedded for the print data in a machine-recognizable manner. That is, in the printing device, a unit of generating information to be embedded acquires respective pieces of information of M pages (1≦M≦N), analyzes the acquired respective pieces of information to be embedded, and generates a single piece of information to be embedded merging the respective pieces of information to be embedded based on the analysis result of the respective pieces of information to be embedded, when N-up printing is designated.