We previously reported that the development of silicon nanowire array-supported palladium nanoparticles (SiNA-Pd) and its use in several organic transformations.[1] Herein, we would like to present highly stable and reusable silicon nanowire array–supported metal nanoparticles (SiNA-MNP) and their application to hydrogenation reactions. SiNA-MNP catalysts were prepared by Ag-assisted chemical etching and subsequent deposition of a variety of metals such as Pd, Pt, and Rh. Monometallic SiNA-Pd catalyzed the hydrogenation of alkenes and alkynes to give the corresponding alkanes in up to 99% yield, and the catalyst was reused without significant loss of its catalytic activities. Moreover, bimetallic SiNA-Pd0.81Rh0.19 and SiNA-Pd0.65Pt0.35 catalysts as well as SiNA-Pd efficiently promoted the hydrogenation of trans-stilbene in EtOH under hydrogen atmosphere (0.1 MPa) to give 1,2-diphenylethane in 99% yield. SiNA-MNP catalysts were readily recovered and reused many times (SiNA-Pd: 170th use on going, SiNA-Pd0.81Rh0.19: 110th use on going, SiNA-Pd0.65Pt0.35: 200th use on going) without loss of their catalytic activity. References [1] Y. M. A. Yamada, Y. Yuyama, T. Sato, S. Fujikawa, Y. Uozumi, Angew. Chem. Int. Ed. 2014, 53, 127-131.