A positioning device comprising a positioning calculation unit (105, 107, 108, 109, 155, 156) adapted to perform positioning calculation by using a state quantity including an ionospheric residual and a tropospheric residual that remains after error correction processing is performed on observation data from a positioning satellite, wherein the positioning calculation unit (105, 107, 108, 109, 155, 156) includes: - a time extrapolation calculation unit adapted to perform time extrapolation calculation on a state quantity of a past epoch including the ionospheric residual and the tropospheric residual to estimate a state quantity of a current epoch including the ionospheric residual and the tropospheric residual; - a residual calculation unit adapted to calculate a double difference residual by using double difference data obtained by double difference calculation on the observation data, a geometric distance between the positioning satellite and the positioning device obtained from the observation data, and the state quantity of the current epoch estimated by the time extrapolation calculation unit; and - an observation update calculation unit adapted to perform observation update calculation using the double difference residual to update the state quantity of the current epoch estimated by the time extrapolation calculation unit, wherein the observation update calculation unit is adapted to perform observation update calculation based on an assumption that a value of the ionospheric residual included in the double difference residual is zero to update the state quantity of the current epoch including at least the ionospheric residual and estimated by the time extrapolation calculation unit, characterized in that the observation update calculation unit is adapted to perform observation update calculation based on an assumption that a value of the tropospheric residual included in the double difference residual is zero to update the state quantity of the current epoch including at least the tropospheric residual and estimated by the time extrapolation calculation unit. - a time extrapolation calculation unit adapted to perform time extrapolation calculation on a state quantity of a past epoch including the ionospheric residual and the tropospheric residual to estimate a state quantity of a current epoch including the ionospheric residual and the tropospheric residual; - a residual calculation unit adapted to calculate a double difference residual by using double difference data obtained by double difference calculation on the observation data, a geometric distance between the positioning satellite and the positioning device obtained from the observation data, and the state quantity of the current epoch estimated by the time extrapolation calculation unit; and - an observation update calculation unit adapted to perform observation update calculation using the double difference residual to update the state quantity of the current epoch estimated by the time extrapolation calculation unit, wherein the observation update calculation unit is adapted to perform observation update calculation based on an assumption that a value of the ionospheric residual included in the double difference residual is zero to update the state quantity of the current epoch including at least the ionospheric residual and estimated by the time extrapolation calculation unit, characterized in that the observation update calculation unit is adapted to perform observation update calculation based on an assumption that a value of the tropospheric residual included in the double difference residual is zero to update the state quantity of the current epoch including at least the tropospheric residual and estimated by the time extrapolation calculation unit.