To improve the throughput of substrate bonding. A substrate bonding apparatus that bonds first and second substrates so that contact regions in which the first and second substrates contact are formed in parts of the first and second substrates and the contact regions enlarge from the parts, the apparatus including: a detecting unit detecting information about the contact regions; and a determining unit determining that the first and second substrates can be carried out based on the information detected at the detecting unit. In the substrate bonding apparatus, the information may be information, a value of which changes according to progress of enlargement of the contact regions, and the determining unit may determine that the first and second substrates can be carried out if the value becomes constant or if a rate of changes in the value becomes lower than a predetermined value.