METHOD OF PRODUCING GUEST-FREE SILICON CLATHRATE, APPARATUS FOR PRODUCING GUEST-FREE SILICON CLATHRATE

[Problem] To improve productivity of guest-free silicon clathrates [Solution] A method of producing a guest-free silicon clathrate includes a synthesizing step of performing a heat treatment on a mixture containing Si as a material serving as a host and a material serving as a guest to synthesize a silicon clathrate compound; and a guest removing step of irradiating the silicon clathrate compound contained in a container with an electromagnetic wave to remove the guest while suctioning gas inside the container.