A packet relay device comprises a distribution processing unit classifying traffics into groups and users based on header information of packets received; a calculation unit calculating available frame rate of each user from peak frame rate, minimum frame rate, and weight information set for each user; a scheduling control unit updating a transmission schedule point-in-time calculated based on the available frame rate of each user, and judging which packet should be transmitted in accordance with the transmission schedule point-in-time updated; and a shaping unit updating a transmission schedule point-in-time calculated based on the peak frame rate of each user, and performing a shaping of packets at the peak frame rate on each user basis in accordance with the transmission schedule point-in-time updated; and a priority-control processing unit performing a strict priority control over transmission of packets of each group in correspondence with degree of priority of each group.