A navigation apparatus (121, 131) for displaying navigation information generated based on map information, the navigation apparatus comprising: positional information acquiring means (122, 132, 211) for acquiring positional information; storage means for storing two-dimensional map data, three-dimensional graphic data, and node-based altitude data of recorded altitude data of nodes which are set on a link used as a route; a data processor generating and outputting three-dimensional display information for a guidance region by receiving the positional information acquired by the positional information acquiring means (122, 132, 211), and acquiring data from the storage means based on the received positional information; and display means for displaying the information output from the data processor, wherein the data processor is adapted to calculate the altitudes of points on the route based on the node-based altitude data, and is adapted to generate and output, to the display means, three-dimensional route information in which data of the calculated altitudes is set as a parameter, wherein the storage means is adapted to store, as interpolation-point-based altitude data, altitude information of interpolation points which are each set between nodes, and wherein the data processor is adapted to calculate the altitudes of points on the route based on the interpolation-point-based altitude data, and generates and is adapted to output, to the display means, one of symbol information of a vehicle having the navigation apparatus and three-dimensional route information in which data of the calculated altitudes is set as a parameter, characterized in that the navigation apparatus (121, 131) is adapeted that, in the altitude information of the interpolation points which are each set between nodes, the altitude of only one interpolation point of a set of two adjacent interpolation points having an altitude difference not greater than a predetermined threshold difference value is stored as the interpolation-point-based altitude data in the storage means. positional information acquiring means (122, 132, 211) for acquiring positional information; storage means for storing two-dimensional map data, three-dimensional graphic data, and node-based altitude data of recorded altitude data of nodes which are set on a link used as a route; a data processor generating and outputting three-dimensional display information for a guidance region by receiving the positional information acquired by the positional information acquiring means (122, 132, 211), and acquiring data from the storage means based on the received positional information; and display means for displaying the information output from the data processor, wherein the data processor is adapted to calculate the altitudes of points on the route based on the node-based altitude data, and is adapted to generate and output, to the display means, three-dimensional route information in which data of the calculated altitudes is set as a parameter, wherein the storage means is adapted to store, as interpolation-point-based altitude data, altitude information of interpolation points which are each set between nodes, and wherein the data processor is adapted to calculate the altitudes of points on the route based on the interpolation-point-based altitude data, and generates and is adapted to output, to the display means, one of symbol information of a vehicle having the navigation apparatus and three-dimensional route information in which data of the calculated altitudes is set as a parameter, characterized in that the navigation apparatus (121, 131) is adapeted that, in the altitude information of the interpolation points which are each set between nodes, the altitude of only one interpolation point of a set of two adjacent interpolation points having an altitude difference not greater than a predetermined threshold difference value is stored as the interpolation-point-based altitude data in the storage means.