Abstract: The present invention provides an apparatus which divides ions present in a liquid in a small amount into positive ions, negative ions, and charge density, measures the divided ions and the charge density, and displays amounts thereof. The apparatus further includes a storing function of data thereof. The apparatus has a signal detecting section 21 having a sensor section 5 disposed in an upper portion of a body 1, a signal detecting box A disposed in a lower portion of the body 1, and including therein a hoisting and lowering bench which moves a container C in which liquids to be measured are held to and from the sensor section 5, and a measuring body B for processing a signal output from the signal detecting section 21, detecting and displaying in accordance with an amount of ions, and for outputting impressed voltage to recording function of data and the sensor section.