The article is devoted a ring multibeam interferometer. The last few decades such an interferometer is considered as the most promising sensitive element of inertial microoptical angular velocity sensors. All approaches to microoptical angular velocity sensors design are using only amplitude characteristics of interferometer for determining the angular velocity. Our results indicate that one can use the phase characteristics for the same goal. The method measurement of angular velocity with use of the phase and amplitude characteristics of ring interferometer was developed. The paper considers the advantages of using phase characteristic of ring multibeam interferometer.