The invention provides a seal structure for an electromagnetic lead wire, in which the seal property of the part penetrated by a lead wire of an exciting coil is high. A seal structure (31) for an electromagnet lead wire includes an annular yoke (22) including an annular groove (27), a wiring hole (52) configured to pass a lead wire (42) of an exciting coil (38), an insulating resin (39) configured to seal the exciting coil (38), and a seal member (32) arranged in the hole. The wiring hole (51) includes a though hole (35) of a case (24), and a concave portion (33) of the yoke (22). The insulating resin (39) includes a projecting portion (56) whose distal end face (56a) is located in the concave portion (33). The seal member (32) includes a columnar portion (61) inserted into the though hole (35), and a flange portion (62) located in the concave portion (33). The flange portion (62) is sandwiched and compressed between the device inner surface (24a) of the case (24) and the distal end face (56a) of the insulating resin (39).