The method for detoxifying asbestos disclosed here includes: preparing an asbestos-containing substance that contains at least one type of asbestos; preparing an asbestos treatment agent that contains a mineral acid, N-methyl-2-pyrrolidone and a fluoride; and bringing the asbestos-containing substance into contact with the asbestos treatment agent so as to detoxify asbestos in the asbestos-containing substance. Due to this configuration, asbestos in the asbestos-containing substance can be favorably detoxified.