PROBLEM TO BE SOLVED: To provide a system handling treating liquid which can correctly measure microvolume of a transfer liquid that is to be dispensed, by measuring the corresponding change in pressure. SOLUTION: The microvolume liquid treating system 10 includes a microdispenser 16 employing a piezoelectric transducer attached to a glass capillary; a positive displacement pump 12 filling a transfer liquid into the microdispenser and sucking the transfer liquid from the microdispenser, controlling the pressure of the liquid of the system, and cleaning the microdispenser between liquid transfers; and a pressure sensor 14 for measuring the pressure of the liquid of the system and producing a corresponding electrical signal. The pressure signal is used to verify and measure the volume of the transfer liquid which is dispensed, and to perform automated calibration and diagnosis of the microdispenser. COPYRIGHT: (C)2008,JPO&INPIT