Provided is a turbo compressor. The turbo compressor includes a driving shaft, a first impeller, a second impeller, a first shroud, a second shroud, a first-stage outflow passage, and a second-stage outflow passage. Also, the turbo compressor includes a gap adjustment passage that is branched from at least one of the first-stage outflow passage or the second-stage outflow passage to extend to the first shroud.