This paper briefly summarizes our recent work on the characterization of atom-resolved surface images of TiO2(110) composed of Ti atoms, O atoms, defects and hydroxyls by scanning tunneling microscopy (STM) and non-contact atomic force microscopy (NC-AFM). The paper also presents new kinetic aspects in the catalytic dehydration and dehydrogenation of formic acid on the characterized surface. Switchover of the reaction path from the dehydration to the dehydrogenation occurred by the presence of formic acid undetectable at the surface, where acidic formic acid molecules opened the basic catalysis. In situ STM observation revealed that the dehydrogenation reaction at 400–450 K was strongly suppressed in the vicinity of single-atom height steps. The suppressive effect of step ranged over 2.4 nm into terrace. It is likely that the catalyst with flat surfaces larger than 5 nm is active for the dehydrogenation of formic acid.