This is an analysis result of the radio spectrum of CS molecular gases (rotational transition J=3-2, 146.969026 GHz) in a celestial object called Orion KL, which was obtained using the first ACA 12-m antenna. The spectrum around 146.945GHz was generated from the apparent vibration of the frequency due to the Doppler Effect between the target object and the observer. The spectrum appears to be slightly splayed out at the both ends: the spectrum of this shape is called “outflow,” which is frequently observed in star-forming regions. Since the spectrum was obtained with the intensity equivalent to those observed with other telescopes, it was confirmed that the ACA antenna fully demonstrated its radio-wave collecting capability.