PURPOSE: To prevent damage to a thermal shock, etc. by using a metallic pipe as the main body of a duct and executing a ceramic layer onto the inner circumferential surface of the metallic pipe.

CONSTITUTION: An induction coil 3 is mounted onto the outer circumference of a duct 1 for an electromagnetic pump through a yoke 2, and a core 4 is set up at the central section of the inside of the duct 1. The duct 1 is constituted in such a manner that a ceramic layer 6 such as alumina is executed onto the inner circumferential surface of a metallic pipe 5 shaped by nonmagnetic stainless, etc., a spiral holding groove 7 is formed to the outer circumferential surface of the metallic pipe 5, a heating wire 8 is wound on the groove 7 and the outer circumferences of these wire and the pipe 5 are coated with a heat- insulating material 9 at that time. Accordingly, melting-resistant metallic properties can be ensured in the duct 1, thus improving durability.