An anti-shake device for use in an optical system comprises a biaxial rotating element and a electromagnetic driving module. The biaxial rotating element is made by grooving a thin resilient plate to form a special multiple-frame structure. The biaxial rotating element, when driven by the electromagnetic driving module, makes limited pivotal movement about two axes so as to provide shake compensation. The electromagnetic driving module, composed of a plurality of permanent magnets and a plurality of coils, is supported and positioned by an inner support frame and an outer support frame, both of which have uniquely designed structures. The resultant anti-shake device is structurally simple, easy to assemble, compact in size, and relatively low-cost.