In a liquid dispensing apparatus comprising a dispensing probe for sipping and injecting a liquid sample and a dispensing controller for operating the dispensing probe to ascend, descend and rotate, the liquid dispensing apparatus includes a sample moving device for moving a rack holding the liquid sample, a light beam generator, a photosensor for receiving a light beam reflected from a surface of the liquid sample, a computing unit for computing a liquid surface level based on an output signal from the photosensor, and a controller for controlling operations of those components in a supervising way and processing information necessary for the operations. With the liquid dispensing apparatus, precise information of the liquid surface level can be obtained before the start of the dispensing operation.