A network evaluation apparatus that evaluates a design of an optical network, the network evaluation apparatus including: a processor that selects two nodes, between which a lightpath is to be set up, from a plurality of nodes based on a traffic volume demand values, calculates a decreased amount of cost based on numbers of the plurality of nodes and a plurality of routers for relaying a signal transmitted between the two nodes selected, calculates an increased amount of cost based on a transmission distance of the lightpath and a number of a plurality of repeaters to be inserted according to a segment distance, and determines a value of the optical network based on the decreased amount of cost and the increased amount of cost.