A position detection system comprising a plurality of master devices (110, 120, 130, 140) surrounding a measurement area, and a slave device positioned in the measurement area, and configured to measure a position of the slave device using high-frequency signals, the position detection system configured to execute: a first process that measures distances between the slave device and each of the plurality of master devices (110, 120, 130, 140) a plurality of times, to obtain a minimum value of each of the distances; and a second process that obtains a position of an intersection point of two arcs among a plurality of arcs respectively having the minimum value of each of the distances as a radius from respective centers of the plurality of master devices (110, 120, 130, 140) when a number of intersection points of the two arcs within the measurement area is one, characterised in that the position detection system is further configured to: determine whether or not each of distances between two of the plurality of intersection points is less than or equal to a predetermined value; repeat the first and second processes if any distance between two of the plurality of intersection points is greater than the predetermined value; and execute a third process that regards a center of gravity of the plurality of intersection points as a true position of the slave device when each of distances between two of the plurality of intersection points is less than or equal to the predetermined value. a first process that measures distances between the slave device and each of the plurality of master devices (110, 120, 130, 140) a plurality of times, to obtain a minimum value of each of the distances; and a second process that obtains a position of an intersection point of two arcs among a plurality of arcs respectively having the minimum value of each of the distances as a radius from respective centers of the plurality of master devices (110, 120, 130, 140) when a number of intersection points of the two arcs within the measurement area is one, characterised in that the position detection system is further configured to: determine whether or not each of distances between two of the plurality of intersection points is less than or equal to a predetermined value; repeat the first and second processes if any distance between two of the plurality of intersection points is greater than the predetermined value; and execute a third process that regards a center of gravity of the plurality of intersection points as a true position of the slave device when each of distances between two of the plurality of intersection points is less than or equal to the predetermined value. determine whether or not each of distances between two of the plurality of intersection points is less than or equal to a predetermined value; repeat the first and second processes if any distance between two of the plurality of intersection points is greater than the predetermined value; and execute a third process that regards a center of gravity of the plurality of intersection points as a true position of the slave device when each of distances between two of the plurality of intersection points is less than or equal to the predetermined value.