In a bookbinding apparatus (1) comprising an adhesive tank (23) for retaining therein an adhesive melted by heat, a roller (24) ratatably supported with the adhesive tank so as to dip a lower portion thereof in the adhesive retained in the adhesive tank, for applying the adhesive to a sheet stack along a lateral edge thereof, and a holding unit (18) capable of holding the sheet stack, an adhesive tank carrier (76, 78), the movably constituted adhesive tank (23) and the roller (24) are disposed at a stand-by position located outside a longitudinal end face of the sheet stack held by the holding unit (18) in a stand-by stage so that the adhesive tank is contactlessly heated to melt the adhesive, and are moved together from the stand-by position in a longitudinal direction of the sheet stack substantially through an entire area under a back face thereof in a bookbinding stage.