A positioning apparatus, including: positioning calculation devices for positioning for a plural antenna, to acquire positioning results indicating the antennas positions and accuracy indices indicating accuracies of the positions, the antennas receiving GPS satellites signals and having a known distance between each antennas; and a determination device including: a determination unit performing first determination whether accuracies indicated by the accuracy indices of two antennas out of the plural antenna is higher than a first threshold and second determination whether a difference between a measured distance between the two antennas based on a difference between positioning results of the antennas and an actual distance therebetween is smaller than a second threshold, to thereby acquire a reliability index (RI) and a final positioning result (FPR) based on the two determinations; and an output signal generation unit for generating positioning information for controlling a human interface (HI) to notify a result based on the (FPR) and (RI).