PURPOSE: To reduce a melted loss of a corrosive element in an electromagnetic pump, by using high manganese steel under a good non-magnetic condition for a main member that is put in contact with a magnesium-based melted metal.

CONSTITUTION: In an electromagnetic pump, a coil is provided around a duct made of high manganese steel containing an Ni element less than 1.0%, or preferably less than 0.1%. Anyway, a deterioration in carbon content is caused and the weldability is reduced when martensitic transformation is avoided in manufacturing. An austenite phase is made stable when steel has a high content ratio of manganese of 25 to 30%. When a duct with large curvature or a small thickness is necessary, the duct in a given shape can be obtained in a hot working step or in repeated steps of work and annealing. Then, the anti-corrosive property of the product is improved with a small melted loss, by reducing a loss of an Fe element melted into a mangnesium-based melted metal.