Inspection Device and Inspection Method Using Inspection Device

An inspection device includes: an inspection coil disposed between a first feeder line and a second feeder line; and a cover formed to cover a core. The cover includes: a coil cover portion covering the inspection coil; and a projection portion formed to project to both sides at least in a specific radial direction with respect to the coil cover portion. The dimension in the specific radial direction of the coil cover portion is smaller than the design interval between the first feeder line and the second feeder line, and the dimension in the specific radial direction of the projection portion is larger than the design interval.