A sensitive and practicable temperature control material which precisely or determinably detects whether the temperature reaches a predetermined temperature by electrical change from a conductive state to an insulated or lower-conductive state has excellent time stability, chemical stability, durability, and weather resistance. The temperature control material includes a heat-melt substance which melts by heat at a melting point according to temperature being detected, and a conductive paste which includes conductive powder. The temperature control material is in a conductive state by the conductive paste. The heat-melt substance is kept away from the conductive paste through a porous material and the temperature control material changes to be in an insulated or lower-conductive states. The heat-melt substance penetrates the porous material to irreversibly permeate and/or disperse into the conductive paste on a heat-melt state thereof.