A multi-phase metal hydride alloy material which is capable of reversibly absorbing and desorbing hydrogen includes a first main phase or group of phases having an ABx type crystalline structure and a second phase which has a concentration of a modifier element therein which is greater than the concentration of the modifier element in the first phase or group of phases. The probe includes a tip positionable over the substance on the substrate. When an identifier assignment release request is received from an identifier control portion 100 of the terminal side device in a usual state, the dynamic identifier assigning portion changes the state of an identifier assigned to the terminal side device to the non-assigned state. A through hole penetrating in a direction crossing to the fastening groove in the first fastening member and a through hole penetrating in a direction crossing to the fastening groove in the second fastening member are provided with fastening devices. An optical fiber with air holes of a predetermined size and shape along the length of the optical fiber is drawn by supplying nitrogen gas into air holes through one end of a holey optical fiber preform while heating the other end of the preform.