Abstract: A magnetic detection-tag deactivating apparatus for deactivating a magnetic detection-tag, having preferable operability when deactivating operation, and further enabling to increase accuracy of deactivation, includes: at least one or a plurality of deactivating rollers, disposing one or more cylindrical unitary permanent magnets, on a periphery surface of which is magnetized to N-pole and/or S-pole, along an axial direction thereof, whereby deactivating the magnetic detection-tag through a relative movement between the magnetic detection-tag and the deactivating roller. Herein, it is preferable that the deactivating roller is provided in rotatable manner.

Abstract: A compact magnetic object detection device with high degree of freedom for installation can be provided. The magnetic object detection device includes magnetic field generating mechanism for radiating an alternating magnetic field in a vicinity space; one or a plurality of loop antennas which convert the magnetic field in the vicinity space into an electric signal; determining mechanism for analyzing an existence of magnetostriction and determining an existence of a magnetic object, the magnetostriction generated by the magnetic object existing in the vicinity space based on the electric signal of each of the loop antennas. An installation member, attached with at least the magnetic field generating mechanism and each of the loop antennas, has a pole shape.

Abstract: A loop antenna is constructed by bending a linear conductor so that it forms concavo-convex portions within an antenna plane.