A glycosidase inhibitor comprising as an active ingredient an extract of Ascophyllum nodosum which is a kind of brown algae can be used as a useful healthy food or food for specified health uses for the treatment andor prevention of diabetes. In this case, the contact metallization layer is covered with a radiation-transmissive, electrically conductive contact layer. Opening the stop or removing it from the beam path permits the entire image to be scanned with the image sensor. Both of the plan views of the cassette block and the vacuum processing block are nearly rectangular, and the width of the cassette block is designed larger than the width of the vacuum processing block, and the plan view of the vacuum processing apparatus is formed in an L-shape or a T-shape. Program code is automatically generated for directing the programmable circuit at run-time deployment to transform actual input data units of the defined type of input data units to actual output data units having the desired output data format in a manner corresponding to the graphical transformation of the input data format to the desired output data format. The polarity exchanger and ion implanter having the polarity exchanger may prevent generation of metallic contaminants caused by a flow rate variation of the stripping gas or deterioration of a component of the gas circulation unit.