This paper presents a 26.5 GHz beam switching reflectarray monolithically fabricated on glass substrate with the RF MEMS switches. The array is formed using 10x10 aperture coupled microstrip patch antenna (ACMPA) elements. RF MEMS switches are implemented on the transmission lines in order to sustain the beam switching. A prototype of a reflectarray with 90 RF MEMS switches is monolithically produced using an in-house surface micromachining process including the wafer bonding steps. The measurement result shows that the beam can be switched to similar to 40 degrees as required.