We describe the design, fabrication and characterization of a biaxial torsional scanning mirror for use in a microfabricated confocal optical microscope. The mirror, fabricated using wafer bonding and surface micromachining techniques, is a gimbal structure consisting of a silicon plate, measuring 500 micrometers X 500 micrometers X 25 micrometers , which is suspended in a silicon frame by silicon nitride hinges. It is actuated electrostatically, and is capable of raster scanning with a line scan frequency of 2.7 kHz and with a scan range of +/- 1.5 degree(s) about both orthogonal axes. Both resonant and non-resonant scanning are discussed. Sample images acquired with a frame rate of 10 Hz using a microfabricated microscope with the biaxial scanning mirror are presented.