Recent experiments related to macro- and micro-instabilities in the GAMMA 10 tandem mirror are described. A stability boundary of a flute interchange mode was revealed experimentally. The pressure anisotropy becomes strong with an increase in the beta value in the central cell. The critical beta of the central cell for the flute interchange mode depends on the pressure anisotropy. The Alfven ion-cyclotron (AIC) mode which is driven by the anisotropy in the velocity space is spontaneously generated well below the theoretically predicted absolute boundary. The performance of the macro- and micro-stabilities in ICRF-heated plasma of the central cell is related to the pressure anisotropy.