This paper describes the output voltage characteristics of the metal core piezoelectric ceramic fiber/aluminum composite. In this study, the thin patch type device developed by Interphase Forming/Bonding Method in the previous study was evaluated by the oscillation test. As the result, the output voltage from the device was proportional to its strain, independent of its strain rate and changed with its strain direction. In addition, it was also cleared that the phase difference between the output voltage and the displacement of the oscillation plate was changed at a certain strain direction by the difference between the longitudinal piezoelectric constant and the transverse one.