A network apparatus for a stable handoff in an IP-based mobile ad hoc network system and a handoff method using the same. Present invention enables a handoff to be stably performed by pre-configuring a handoff to a new access router. The network apparatus of the present invention comprises a movement-determining unit for determining movement depending on the signal strength upon reception of a packet among network apparatuses operating on a communication mobile ad hoc network, and deciding a handoff to a new access router; a router-configuring unit for configuring information on the new access router for the handoff by performing beforehand the handoff to the new access router according to the results of the determination in the movement-determining unit; and a handoff-processing unit for performing the handoff to the new access router using the pre-configured information according to the determination in the movement-determining unit.