A determination device that determines quality of target portion based on sensor data obtained by a sensor measuring the target object, includes one or more processors configured to acquire sensor data representing the target portion, acquire information indicating a changed portion, determine whether the target portion includes the changed portion based on acquired information, determine a first label of the target portion represented in the sensor data by using a determination model learned from a training dataset based on training target portions, the first label representing target portion as one of good, defect, and a defect candidate, accept a second label of the target portion input via a user interface when the target portion includes the changed portion or when the first label of the target portion is determined as the defect candidate, and perform quality determination of the target portion based on the first label and/or the second label.