Abstract: A magnetic core housing capable of applying a sufficient force to a magnetic core is provided. A magnetic core housing according to an aspect of the disclosure includes first and second housings each capable of housing a core, a hinge configured to connect the first and second housings with each other so that they can be opened and closed with respect to each other, and a metal spring disposed in the first housing. The metal spring includes a planar part and a pair of spring parts, and also includes reinforcing means for preventing the planar part from being bent due to a force transmitted from the pair of spring parts when the core is housed in the first housing.