To provide a method for assembling a displacement sensor in which the assembling work is simple.

The method for assembling the displacement sensor 1L, as the method for assembling the displacement sensor 1L for performing the detection by performing magnetoelectric conversion of the displacement of a sheet, includes a magnetic body disposing step, for disposing at prescribed positions a hard magnetic body 5L rotating under the interconnection with the displacement of the sheet and a soft magnetic body 3L, together with the hard magnetic body 5L, for forming a magnetic circuit; and a magnetization step for magnetizing the hard magnetic body 5L, from the outer circumferential sides of the hard magnetic body 5L and the soft magnetic body 3L disposed at the prescribed positions.