PURPOSE: To obtain a pastelike contact medium for ultrasonic measurement which is sanitary and washable and can be easily used at any place while providing rust- resisting effect without containing oil.

CONSTITUTION: To a low molecular component of hydrophilic polyalkylene oxide which is liquid at the normal temperature, e.g. polyethylene oxide having 200W400 molecular weight, if necessary, water is added and with the mixture, a high molecular component which is solid at the normal temperature, e.g. polyethylene oxide having 1,000W6,000 molecular weight is mixed to obtain a pastelike material. Then, caustic alkali is added to keep about 8pH, and further one or ≥2 kinds among well- known anticorrosives are added to manufacture said medium.