Provided is an apparatus and method for estimating sensor signals to stabilize a posture of a mobile satellite tracking antenna. The apparatus includes: an angular velocity estimating unit for estimating an angular velocity signal by removing an error signal generated from an input angular velocity sensor signal through a first low frequency band filtering operation; and an inclination angle estimating unit for estimating an inclination angle signal by receiving an inclination angle sensor signal, extracting low frequency component of inclination angle signal through performing a second low frequency band filtering operating on the received inclination angle sensor signal, obtaining an inclination angle integrating signal through integrating the estimated angular velocity signal, extracting high frequency component of inclination angle signal through performing a high frequency band filtering operation on the inclination angle integrating signal, and adding the extracted low frequency component and high frequency component of inclination angle signal.