The invention relates to apparatus for manufacturing expansion-molded articles capable of manufacturing expansion-molded articles continuously by conveying foamed beads into a heating region sandwiched between upper and lower belts and foaming by heating, and consists in apparatus for manufacturing expansion-molded articles constituted such that the thickness or width of the expansion-molded article can be altered. The manufacturing apparatus of the invention consists in manufacturing apparatus for manufacturing molded articles, comprising a belt that continuously travels along the upper inside face of a passageway, defined by structural members, whose cross-section constitutes an approximately rectangular shape and a belt that continuously travels along the lower inside face thereof, by continuously molding foamed beads by successively passing foamed beads supplied between these upper and lower belts through a heating region and cooling region sandwiched between these belts, in which, by constituting at least one of the upper and lower structural members that form the passageway so as to be capable of movement in the vertical direction sandwiched between the side-face structural members a construction is achieved such that the thickness of the expansion-molded article that is sought to be obtained can easily be varied, or, by constituting at least one of the side-face structural members that form the passageway so as to be capable of movement in the lateral direction sandwiched between the upper and lower structural members a construction is achieved such that the width of the expansion-molded article that is sought to be obtained can easily be varied.