A positioning device includes an estimated height storage section which stores an estimated height H1, a signal reception section which receives a satellite signal which is a signal from a satellite positioning system (SPS) satellite, a two-dimensional height calculation section which calculates a two-dimensional height H2c by two-dimensional positioning using the estimated height H1, a three-dimensional height calculation section which calculates a three-dimensional height H2b by preliminary three-dimensional positioning during two-dimensional positioning, a height selection section which selects the two-dimensional height H2b or the three-dimensional height H2c in order to update the estimated height H1, and an updating section which updates the estimated height H1 with the two-dimensional height H2b or the three-dimensional height H2c selected by the height selection section.