PURPOSE: To elevate image resolution, by shifting a pitch of a magnetized body and a pitch of a magnetic reluctance effect type element of a detector, by making them have a prescribed relation, in a magnetic linear encoder for relatively moving a magnetized body substrate and the detector.

CONSTITUTION: On a magnetic medium substrate 1, a high magnetic force ferromagnetic thin film 2 patterned by a pitch (λ) and magnetized in the X direction is provided. On the other hand, on a detector substrate 3 moving relatively with the substrate 1, a high magnetic force ferromagnetic film 4 and a uniaxial and anisotropic magnetic reluctance effect type element 5 are formed by a pitch of (m+1/n).λ(m and n are integers). Also, each element 5 is magnetically biased by a leakage magnetic field of the high magnetic force ferromagnetic film 4.