We report a 1xN rotary optical switching mirror actuated by an electrostatic comb-driver for the optical networking. A variety of MEMS optical switching mirrors have been recently proposed. Some of these devices utilize surface micromachined films as reflection micromirrors and result in optical degradation. Some of these devices fabricated by bulk micromachining highly rely on delicate assembly for the micromirrors to the top of the actuators. In this paper, we focus on developing a rotary optical switching micromirror with no need of delicate assembly. The rotary actuator and the switching micromirror are both fabricated by deep RIE in our design. We use the Spin-On-Glass (SOG), which is used as the intermediated layer in the low temperature boning, to fabricate a rotary MEMS optical switching mirror with self-assembly. We successfully assemble the micromirror on top of the rotor stage of the rotary actuator. Experimental results show that our rotary vertical micromirror rotates about 1.5° under 150 volts. The first vibration mode of this rotary switching MEMS mirror is a rotary mode and appears around 3.4 kHz, which is measured via a Polytec laser doppler vibrometer.