Provided is a magnetic marker detection method with high detection reliability. The magnetic marker detection method for detecting a magnetic marker (10) laid on a road while a vehicle (5) having a plurality of, at least two or more, magnetic sensors attached thereto is travelling includes a gradient generating process of generating a first magnetic gradient, which is a difference between magnetic measurement values of two magnetic sensors and a filter processing process of generating a filter output value by performing filter processing by a high-pass filter as to a change of the first magnetic gradient in a travelling direction of the vehicle. The magnetic marker (10) is detected by an arithmetic operation process regarding the filter output value.