A sorter includes a plurality of receiver members for receiving a workpiece, and a rotary circulating mechanism driven by a driving unit to circulate along a circulatory path. The circulating mechanism mounts the receiver members to be pivotable about a first pivot axis. On the circulatory path of the rotary circulating mechanism, each receiver member is switchable between an extended posture at which the receiver member is capable of receiving the workpiece and a folded posture at which the receiver member is pivotally folded about the first axis to the vicinity of the rotary circulating mechanism. Each receiver member has at least one second pivot axis. Also, each receiver receiver member includes a plurality of receiver elements which are pivotable relative to each other about the second pivot axis and an extended-posture maintaining mechanism interposed between the adjacent receiver elements for maintaining the receiver elements at a predetermined posture when the receiver member assumes the extended posture.