Disclosed is an apparatus and method for processing documents to extract expressions and descriptions. The apparatus for processing documents includes a document collection unit, which collects documents from websites and divides each of the collected documents into a script portion and a description portion to thus generate a script document and a description document, and an expression extraction unit, which extracts expression description sentences on the basis of the description document, and extracts expressions described by the expression description sentences from the script document. According to the invention, study material, including a pair that comprises an expression to be studied and a description thereof, can be automatically constructed.