A method of installing a stroke sensor that enables the stroke sensor to be adjusted in a simple process is provided. The method has the steps of: arranging a second magnet, relative to the magnetic field detecting element, at a physically determinable first reference position and obtaining an indicator value S1; attaching the first magnet and the magnetic field detecting element to structures different from each other, respectively, and positioning the first magnet, relative to the magnetic field detecting element, at a physically determinable second reference position, and obtaining an indicator value S2, wherein the second reference position corresponds to the first reference position; calculating ΔS=S1−S2, wherein ΔS is a difference between the indicator value S1 and the indicator value S2; and modifying a process in the processor such that a sum of the indicator value S and ΔS is outputted.