A pressurizing apparatus, comprising: a mounting base on which a target object is mounted; an upper mold for pressurizing the target object mounted on the mounting base from an upper side thereof; a heating lower mold that is a lower mold heated beforehand by heating means and is configured to heat the target object while pressurizing it in a state where the mounting base is sandwiched between the upper mold and the heating lower mold; a cooling lower mold that is a lower mold cooled beforehand by cooling means and is configured to cool the target object while pressurizing it in a state where the mounting base is sandwiched between the upper mold and the cooling lower mold; a side mold disposed around the upper mold and, when closely contacting with the mounting base, forming a hermetically closed space around the target object together with the upper mold and the mounting base; a suction apparatus (42, 44) for sucking air from the hermetically closed space to bring the surrounding of the target object into a vacuum state; and a control device for controlling the driving of the molds in such a way as to switch the lower mold contributing to the pressurization of the target object to the heating lower mold or the cooling lower mold according to the state of progress in pressurization processing for the target object, wherein the control device is configured, prior to the pressurization of the target object, to bring the side mold into contact with the mounting base to form the hermetically closed space and to drive the suction apparatus (42, 44) to bring the hermetically closed space into the vacuum state. a mounting base on which a target object is mounted; an upper mold for pressurizing the target object mounted on the mounting base from an upper side thereof; a heating lower mold that is a lower mold heated beforehand by heating means and is configured to heat the target object while pressurizing it in a state where the mounting base is sandwiched between the upper mold and the heating lower mold; a cooling lower mold that is a lower mold cooled beforehand by cooling means and is configured to cool the target object while pressurizing it in a state where the mounting base is sandwiched between the upper mold and the cooling lower mold; a side mold disposed around the upper mold and, when closely contacting with the mounting base, forming a hermetically closed space around the target object together with the upper mold and the mounting base; a suction apparatus (42, 44) for sucking air from the hermetically closed space to bring the surrounding of the target object into a vacuum state; and a control device for controlling the driving of the molds in such a way as to switch the lower mold contributing to the pressurization of the target object to the heating lower mold or the cooling lower mold according to the state of progress in pressurization processing for the target object, wherein the control device is configured, prior to the pressurization of the target object, to bring the side mold into contact with the mounting base to form the hermetically closed space and to drive the suction apparatus (42, 44) to bring the hermetically closed space into the vacuum state.