A surveillance position determining apparatus for an own aircraft comprising: - a memory that is adapted to store map information including a predetermined surveillance target region; - a cell divider that is adapted to divide the map information stored in the memory into a plurality of cells in a grid on a horizontal plane; - a score determiner that is adapted to determine scores for respective candidate cells (Ca), the scores each being based on easiness of viewing from the aircraft and difficulty of being viewed from a surveillance target which are quantified, and the candidate cells (Ca) excluding multiple surveillance target cells included at least in the surveillance target region, among the plurality of cells; - a surveillance position setter that is adapted to set surveillance positions on a basis of the respective scores of the candidate cells (Ca) determined by the score determiner; and. wherein the score determiner is adapted to determine the respective scores of the candidate cells (Ca) for each of the surveillance target cells, and to determine total scores for the respective candidate cells (Ca), the total scores each being a sum of the scores of the corresponding one of the candidate cells (Ca), and the surveillance position setter is adapted to set the surveillance positions on a basis of the respective total scores of the candidate cells (Ca); wherein the score determiner is adapted to set, among the plurality of cells, the cells that are included inside of a circle having a radius of a surveillance maximum distance around a single surveillance target cell and are not included in a surveillance prohibited region that includes the surveillance target region and that is set at a range provided with a surveillance risk distance around the entire circumference of the surveillance target region, as the candidate cells (Ca) for the single surveillance target cell; wherein the memory is adapted to store, in advance, an evaluation table (156a to 156f) that quantitatively evaluates suitability of the respective candidate cells (Ca) as the surveillance positions, and the score determiner is adapted to determine the respective scores of the candidate cells (Ca) on a basis of the evaluation table (156a to 156f) stored in the memory. - a memory that is adapted to store map information including a predetermined surveillance target region; - a cell divider that is adapted to divide the map information stored in the memory into a plurality of cells in a grid on a horizontal plane; - a score determiner that is adapted to determine scores for respective candidate cells (Ca), the scores each being based on easiness of viewing from the aircraft and difficulty of being viewed from a surveillance target which are quantified, and the candidate cells (Ca) excluding multiple surveillance target cells included at least in the surveillance target region, among the plurality of cells; - a surveillance position setter that is adapted to set surveillance positions on a basis of the respective scores of the candidate cells (Ca) determined by the score determiner; and. wherein the score determiner is adapted to determine the respective scores of the candidate cells (Ca) for each of the surveillance target cells, and to determine total scores for the respective candidate cells (Ca), the total scores each being a sum of the scores of the corresponding one of the candidate cells (Ca), and the surveillance position setter is adapted to set the surveillance positions on a basis of the respective total scores of the candidate cells (Ca); wherein the score determiner is adapted to set, among the plurality of cells, the cells that are included inside of a circle having a radius of a surveillance maximum distance around a single surveillance target cell and are not included in a surveillance prohibited region that includes the surveillance target region and that is set at a range provided with a surveillance risk distance around the entire circumference of the surveillance target region, as the candidate cells (Ca) for the single surveillance target cell; wherein the memory is adapted to store, in advance, an evaluation table (156a to 156f) that quantitatively evaluates suitability of the respective candidate cells (Ca) as the surveillance positions, and the score determiner is adapted to determine the respective scores of the candidate cells (Ca) on a basis of the evaluation table (156a to 156f) stored in the memory.