The conventional tunneling spectrometer gives the uncalibrated second derivatived2V/dI2versus applied voltage (V) of the junction current‐voltage curve (I‐V). However, the calibrated second derivatived2I/dV2is more useful for accurate comparison with theory and can be applied to negative resistance devices. We report here a single electronic instrument for calibrated measurements of all relevant tunneling junction parameters, i.e., dynamic conductance (G), dynamic capacitance (C), current‐voltage curve, and its first and second calibrated derivatives. Moreover, it can measure the derivative of the dynamic capacitance (dC/dV) versus applied potential, which is useful for various types of semiconductor devices. This design is versatile enough to find many laboratory applications where current‐voltage curves are of interest. The circuit, based on a simple design, is accurate to 1% and allows spectral acquisition in about 15 min.