The authors report the fabrication and optical characterization of fully suspended, transferrable, and deflectable silicon photonic crystal nanomembranes. Starting with a silicon-on-insulator wafer, the authors used electron beam lithography and inductively coupled plasma reactive ion etching (ICP-RIE) to introduce various photonic crystal patterns in silicon. A membrane containing the photonic crystal patterns was then defined by photolithography combined with ICP-RIE and released from the handle wafer by wet chemical etching. Finally, a free-standing photonic crystal membrane was obtained by a wet transfer and alignment process over a perforated foreign substrate. In the fabricated structures, the authors observed vivid structural colors in dark-field optical images of square lattice photonic crystals and measured a guided resonance mode with a quality factor as high as 5600 in a novel slot-graphite photonic crystal.