Provided is a technology for detecting abnormal temperature rise of a battery regardless of the number of batteries, and preventing a trouble caused by abnormal temperature rise. A battery production facility (30) for producing a secondary battery (1) comprises an abnormality detector (40) for detecting abnormal state (especially, abnormal temperature rise) of a plurality of secondary batteries (1, 1, . . . ), and a detector (45) for generating a control signal in order to take a predetermined step according to the detection result from the abnormality detector (40). The abnormality detector (40) comprises a low temperature reactant (41) provided in contact with a part of the secondary battery (1) which becomes high temperature easily and reacts at a temperature lower than the temperature at which the secondary battery (1) becomes abnormal state, and a detection sensor (42) for detecting change of the low temperature reactant (41), and detects abnormal state of the secondary battery (1) according to the detection result from the detection sensor (42).