A plasticizing device includes: a material storage unit having a charging port and configured to store pellet-shaped resin pellets; a plasticizing unit having a supply port in communication with the charging port and configured to plasticize at least a part of the resin pellets to generate a shaping material; a coupling pipe having a coupling path coupling the charging port and the supply port; a first material sensor configured to detect a remaining quantity of the resin pellets in the coupling path; and a control unit. The material storage unit includes a material supply mechanism configured to supply the resin pellets to the coupling path, and when the remaining quantity of the resin pellets detected by the first material sensor is less than a first reference value, the control unit controls the material supply mechanism to supply a predetermined quantity of the resin pellets to the coupling path.