1. An emotion information generating apparatus comprising: a processor; a function detector configured to detect an execution state of a first function of a plurality of functions executed by a terminal; an emotion detector configured to detect an interaction of a user with the terminal while the first function is being executed, and convert the detected interaction into emotional data comprising an emotional state of the user of the terminal; a mapping unit configured to map the emotional state of the user to at least one of the first function executed by the terminal and information included in the first function executed by the terminal; a storage unit configured to store the first function in association with the mapped emotional state of the user, wherein the storage unit additionally stores each of the plurality of functions executed by the terminal in association with a corresponding emotional state of the user mapped to each of the plurality of functions; and an output device configured to visually, acoustically, or tactually output a function recommendation based on the emotional state.