A packet transfer device 100 includes a packet classification unit 120 configured to classify received packets, queues 140 for respective classifications, priorities being set to the queues, a dequeue processing unit 150 configured to extract packets from the queue under a predetermined rule based on the priorities set to the queues, and a queue priority control unit 130 configured to perform control, upon detecting that a reception amount of packets related to a communication flow temporarily or intermittently increases from a reception amount under a normal condition, such that a priority of one of the queues holding the packets related to the communication flow is temporarily raised from a priority under the normal condition, during a period while the reception amount of packets related to the communication flow temporarily or intermittently increases.