A packet relay apparatus for suppressing a burst transfer of packets being relayed to improve the quality and reliability of packet communication. In the packet relay apparatus, an arrival time measurement block measures the arrival time of an input packet to generate arrival time information; a packet classification block classifies the packet as an output-interval-control packet, which requires output interval control, or a non-output-interval-control packet, which does not require output interval control, to generate classification information; a packet distribution block receives the packet which has been processed and switched and places the packet in an appropriate queue according to the classification information; and a schedule management block performs relay output control in accordance with the arrival time information such that the output intervals of output-interval-control packets become equal to the input intervals obtained when the packets were input to the apparatus.