Foams, originating from wastewater treatment processes and specifically aeration tanks, usually lead to a decrease of treatment efficiency, which results in several problems such as lower discharge quality, more maintenance cost, outbreak of offensive odors, and riskiness of accidents. Thus both detection probe and fuzzy control system of form are developed in this study based on economical and technical efficiencies. The foam-detecting probes developed is the ends of severed wires, which are virtually costless to manufacture and maintain, so numbers of probes can be installed to obtain the data required for judging the location, size, volume and duration of foam. The experimental results of this study show that both detection probes and fuzzy control system of form can effectively be used to detect form generation and also judge whether or not the form elimination device should be operated.