To provide a node device improving the measurement accuracy of the network communication quality and creating a smaller table for managing statistics information on the communication quality. An importance degree judging section determines the importance degree of a flow by referencing data for judging the degree of importance in the Z-list. An E-list stores statistics data on a flow having a high degree of importance of monitoring. A change judging section makes a judgment on change according to the importance degree of the flow and the importance degree in the E-list. An integral quality calculating section totalizes the qualities of the normal packet information that was measured in a normal packet quality measuring section and the statistics information that was measured in a statistics information quality measuring section and records the total in a quality result section.