We proposed a thin optical system which has pan/tilt and variable focus functions for a small camera. Our optical system is composed of a tunable water prism and a tunable oil lens driven by electrowetting. The optical system can keep its thickness thin, because the oil lens is inside the prism and both of them are controlled on the same plate. In this research, we achieved the optical system capable of shifting the view direction 2 degrees and changing the focal plane from 25 mm to 12.5 mm. The thickness of the optical system is 2.5 mm.