A bookbinding apparatus which makes it possible to shorten a time period required to heat an adhesive when the power of the bookbinding apparatus is turned on again. A glue preparation section heats glue. A glue applying section applies the heated glue to a recording sheet bundle. A CPU of the bookbinding apparatus determines at the power-on of the apparatus whether or not there is a recording sheet bundle to which glue is to be applied within the apparatus. When there is no such recording sheet bundle, the glue applying section applies glue to a recording sheet bundle after the temperature of the glue has reached a first target temperature, whereas when there is such a recording sheet bundle, the glue applying section applies the glue to the recording sheet bundle after the glue temperature has reached a second target temperature lower than the first target temperature.