The present apparatus for measuring data converter comprises a digital-to-analog converter, a multiplexer, a histogram analyzer and a software engine. The digital-to-analog converter is intended to generate uniform pseudo-random signals. The multiplexer selects an output of the digital-to-analog converter or an external analog input signal and sends it to a data converter under test. The histogram analyzer is electrically connected to the output of the data converter under test, so as to display the frequency of the appearance of various codes of the converter. The software engine is electrically connected to the output of the histogram analyzer, so as to display the characteristics of the data converter under test.