To provide a satellite information updating system and the like capable of providing only information representing the necessity of updating of satellite information when the necessity of updating the satellite information arises.

A positioning auxiliary information provision system 30 comprises an auxiliary information producing means for producing positioning auxiliary information containing satellite information, a determination means of satellite information updating necessity for determining the necessity of updating of the satellite information, a satellite information updating necessity information producing means for producing satellite information updating necessity information representing the necessity of updating of the satellite information from the determination result of the satellite information updating necessity determining means, a positioning auxiliary information transmission means for transmitting position information to terminals 80a indicated in provision object terminal information by way of an intermediate device 60, and a satellite information updating necessity information transmission means and the like for transmitting the satellite information updating necessity information to the terminals 80a indicated in the provision object terminal information by way of the intermediate device 60.