A bookbinding apparatus which forms a booklet by coating adhesive onto a spine of a sheet bundle, the bookbinding apparatus comprising: an adhesive tank which stores adhesive; a supplying section which supplies solid adhesive to the adhesive tank; a melting section which melts the solid adhesive supplied to the adhesive tank; a coating section which coats the adhesive onto the spine of the sheet bundle; and a controller which controls the supplying section to supply the solid adhesive from the supplying section to the adhesive tank when an amount of adhesive that has been coated by the coating section reaches equal to or more than a predetermined value.