A positioning satellite selection device that obtains, from signals transmitted from a plurality of positioning satellites, a selection combination at each time of the positioning satellites to be used for positioning at a position of a positioning target, the positioning satellite selection device comprising: - a positioning data acquisition unit to acquire positioning data including navigation information and a range observation value of the plurality of the positioning satellites; - a satellite position calculation unit to calculate a satellite position at each time of the positioning satellite from the navigation information of the positioning data; and - a quality evaluation unit to obtain a quality evaluation value by evaluating quality of the positioning data; characterized by further comprising: - a shortest time designation unit to set a shortest selection time which is a shortest time during which the positioning satellite is selected consecutively in time to a larger value as the quality evaluation value is poorer; - a plan creation unit to obtain the selection combination at each time of the positioning satellites on a condition of selecting for longer than the shortest selection time, by using, as an evaluation criterion, a precision degradation index obtained from a geometric arrangement in the sky at each time calculated from the positions of a plurality of the positioning satellites, select and add an unselected positioning satellite that will best enhance the precision degradation index at a time at which the number of selected satellites is less than an upper limit and the precision degradation index is poorest, and if said positioning satellite is visible at one of neighboring times before and after said time, further select said positioning satellite to select said positioning satellite for longer than the shortest selection time; and - a plan storage unit to store a plan of the selection combination at each time of the positioning satellites. from signals transmitted from a plurality of positioning satellites, a selection combination at each time of the positioning satellites to be used for positioning at a position of a positioning target, the positioning satellite selection device comprising: - a positioning data acquisition unit to acquire positioning data including navigation information and a range observation value of the plurality of the positioning satellites; - a satellite position calculation unit to calculate a satellite position at each time of the positioning satellite from the navigation information of the positioning data; and - a quality evaluation unit to obtain a quality evaluation value by evaluating quality of the positioning data; characterized by further comprising: - a shortest time designation unit to set a shortest selection time which is a shortest time during which the positioning satellite is selected consecutively in time to a larger value as the quality evaluation value is poorer; - a plan creation unit to obtain the selection combination at each time of the positioning satellites on a condition of selecting for longer than the shortest selection time, by using, as an evaluation criterion, a precision degradation index obtained from a geometric arrangement in the sky at each time calculated from the positions of a plurality of the positioning satellites, select and add an unselected positioning satellite that will best enhance the precision degradation index at a time at which the number of selected satellites is less than an upper limit and the precision degradation index is poorest, and if said positioning satellite is visible at one of neighboring times before and after said time, further select said positioning satellite to select said positioning satellite for longer than the shortest selection time; and - a plan storage unit to store a plan of the selection combination at each time of the positioning satellites. - a positioning data acquisition unit to acquire positioning data including navigation information and a range observation value of the plurality of the positioning satellites; - a satellite position calculation unit to calculate a satellite position at each time of the positioning satellite from the navigation information of the positioning data; and - a quality evaluation unit to obtain a quality evaluation value by evaluating quality of the positioning data; characterized by further comprising: - a shortest time designation unit to set a shortest selection time which is a shortest time during which the positioning satellite is selected consecutively in time to a larger value as the quality evaluation value is poorer; - a plan creation unit to obtain the selection combination at each time of the positioning satellites on a condition of selecting for longer than the shortest selection time, by using, as an evaluation criterion, a precision degradation index obtained from a geometric arrangement in the sky at each time calculated from the positions of a plurality of the positioning satellites, select and add an unselected positioning satellite that will best enhance the precision degradation index at a time at which the number of selected satellites is less than an upper limit and the precision degradation index is poorest, and if said positioning satellite is visible at one of neighboring times before and after said time, further select said positioning satellite to select said positioning satellite for longer than the shortest selection time; and - a plan storage unit to store a plan of the selection combination at each time of the positioning satellites.