[Problem] To provide: an antibacterial agent which can exhibit an antibacterial activity even in the presence of an organic substance and can be stored for 1 month or longer a mixed electrolyzed water production device which can be used for the production of the antibacterial agent a sterilization device utilizing the antibacterial agent a mixed electrolyzed water production method which can be used for the production of the antibacterial agent and a sterilization method utilizing the antibacterial agent.[Solution] A mixed electrolyzed water production method involves an electrolysis step of electrolyzing an aqueous solution of sodium chloride and/or potassium chloride to produce acidic electrolyzed water and alkaline electrolyzed water. The method also involves a mixing step of mixing the acidic electrolyzed water and the alkaline electrolyzed water, which have been produced in the electrolysis step, with each other to produce mixed electrolyzed water, wherein the mixing is carried out in such a manner that the resultant mixed electrolyzed water can have a pH value of 4.5 to 7.0. In a sterilization method, mixed electrolyzed water produced by the mixed electrolyzed water production method is attached onto an object to be sterilized. The mixed electrolyzed water thus produced can be used as an antibacterial agent.Le problème décrit par la présente invention est de fournir un agent antibactérien pouvant manifester une activité antibactérienne même en présence dune substance organique et pouvant être stocké pendant 1 mois ou plus un dispositif de production deau électrolysée mélangée pouvant être utilisée pour la production de lagent antibactérien un dispositif de stérilisation mettant en œuvre lagent antibactérien un procédé de production deau électrolysée mélangée pouvant être utilisé pour la production de lagent antibactérien et un procédé de stérilisation faisant intervenir lagent antibactérien. La solution de linvention porte sur un procédé de production deau
