We report hydrogen adsorption on twisted bilayer graphene (tBLG). Raman spectroscopy and the electrical transport properties (electrical resistance and thermoelectric power) confirm the electron doping by hydrogen adsorption, in agreement with the previous report involving exfoliated bilayer graphene (BLG). Common electron doping behaviors were observed at various twist angles (0 degrees, 5 degrees, 12.5 degrees, and 30 degrees), and the adsorptions follow the first-order Langmuir-type adsorption model. Specifically, we analyzed the off-state currents, with band-gap openings of around 13 meV in tBLG with twist angle of 0 degrees, as in Bernal-stacked BLG. (C) 2016 Elsevier B.V. All rights reserved.