A method of treating sewage or waste water for removing nitrogen and phosphorus as well as organic materials in the sewage or waste water, and an apparatus therefor are provided. Coils are provided to generate a substantially uniform magnetic field in the chamber. In another embodiment, a list of internal andor external variables is ranked in order of probability for usage within a selected method call. The LV MOS includes the fourth semiconductor region, a fifth semiconductor region having the second-type conductivity, and a sixth semiconductor region having the first-type conductivity. A sample analyzing method is also disclosed.