A physical quantity data correcting device accurately and rapidly makes corrections of physical quantity data by appropriately controlling an approximate ellipsoid computing unit and/or a correction coefficient computing unit on the basis of a control parameter group. A physical quantity data acquiring unit acquires physical quantity data output from a physical quantity detecting unit that detects physical quantities. A data selecting unit selects the acquired physical quantity data. An approximate ellipsoid computing unit computes an approximate expression of an n-dimensional ellipsoid indicating a distribution shape obtained by distributing the selected physical quantity data in an n-axis coordinate space. A correction coefficient computing unit computes correction coefficients for correcting the computed n-dimensional ellipsoid to an n-dimensional sphere. A computation control unit controls the approximate ellipsoid computing unit and/or the correction coefficient computing unit on the basis of a control p