A new class of magneto-optical switch effect, which does not require to change the direction of the magentic field applied to the sample, was realized in the semimagnetic semiconductor Cd_(1-x)Mn_xTe. This effect was due to the giant Faraday effect of Cd_(1-x)Mn_xTe and the saturation characteristic of the magneto-optical feedback system. The possible applications of the magneto-optical switch for optical and temperature control, and the possibility for realizing the magneto-optical bistability are discussed in this paper..