To provide a potentiometer, having high performance for detecting with high accuracy the rotation angle in the magnetic detection type noncontact type potentiometer.

The non-contact type potentiometer is constituted, providing to arrange facing a pair of magnets 8 and 9 on the rotating shaft 4 of a rotation side, attaching a holder 12 having first and second split grooves 13 and 14 mutually intersecting at the rotation center of a rotating shaft 4, positioned between the pair of the magnets 8 and 9 at the fixed side, mounting first and second magnetic detection components 15 and 16 on the holder 12 so as to be inserted in the first and second split grooves 13 and 14 and detecting the rotation angle of the rotating shaft 4, on the basis of output of the first and second magnetic detection components 15 and 16.