An embodiment packet capture device comprises: a packet receiver configured to receive a packet from a network; a packet retainer configured to store the received packet in a memory to temporarily retain the received packet; a failure detector configured to determine a communication failure is present in the network; a capture controller configured to determine an operation stop address such that retention of packets from the network in time periods before and after a detection time point of the communication failure is ensured when the communication failure is detected by the failure detector; and a capture data generator configured to output the packet stored in the memory as capture data when a storage destination address of the packet stored in the memory has reached the operation stop address or when at least a predetermined waiting time period has elapsed from the detection time point of the communication failure.