Dissolved air flotation (DAF) process has been applied to the entire environmental fields. The micro-bubble generator, which is a key facility in DAF process, can be classified according to its generation methodology. In Korea, saturator and DAF-pump types are widely utilized. The feature of saturator type is the application of an air saturation tank (AST), and it has a disadvantage in that operation and maintenance are not easy due to relatively complicated facilities. On the other hand, DAF-pump type uses a micro-bubble generating pump (MGP) alone, so the device configuration is very simple, but the ranges of optimal operating conditions are narrow. In this study, a new hybrid-type microbubble generator has been developed by linking a pressure pump and an AST by converging the advantages of the existing saturator and DAF-pump types. As a result of examining the operation characteristics of this microbubble generator including operating pressure, air flow rate, water flow rate, power consumption, A/W ratio (air/water ratio), DO, and particle size distribution, the appropriate operating conditions could be determined as operating pressure of 4.0 - 6.0 kgf/㎠, air flow rate of 4.0 - 5.0 L/min, water flow rate of 57 - 68 L/min, and A/W ratio of 5.9 - 8.7%. The average diameter of the generated microbubbles showed a stable distribution in the range of 25.0 - 26.7 μm. Based on the above results, it could be verified that the novel hybrid-type microbubble generator had excellent performance at a level that can be applied to the field.