A wet-type solar battery including a support composed of a light transmissive material and a stack in which a conductive layer, a photoelectric conversion layer containing a porous semiconductor, a porous insulating layer, and a counter electrode conductive layer are stacked in this order is provided. In a biometric authentication system, prior probabilities of enrolled users un and non-enrolled user u0 are previously set. The surfaces to be bonded are polished to a high degree of smoothness and planarity. One end of the torsion-bar spring is secured onto the fastener, and the other end of the torsion-bar spring is received in the slot. The closure body is formed by casting concrete in the access opening subsequent to the introduction of the hazardous material in the storage space and allowing the concrete to harden while supplying heat to the portion of the concrete container body surrounding the access opening.