A centrifugal chiller in which a closed-cycle refrigeration cycle is formed by connecting a compressor, a condenser, an economizer and decompression means forming a multi-stage compression cycle, and an evaporator, with the refrigeration cycle being charged with a low-pressure refrigerant. The condenser and the economizer are integrated with each other by having a portion of their vessel walls form a shared wall, with the base surface of the economizer being positioned below the base surface of the condenser and above the base surface of the evaporator.