An on-off device disposed at each of the inlet and the outlet of a fluid controller is one of five kinds of on-off devices, i. In one embodiment, the contact structure includes a polysilicon conductor and dielectric spacers, wherein each spacer of the dielectric spacer abuts a sidewall of the polysilicon conductor. For measuring a position and orientation of the substrate table, each position detector comprises an optical encoder of a single dimensional or multi dimensional type, the optical encoders being arranged for providing together at least 6 position values, at least one position value being provided for each of the 3 dimensions. The testreset unit is spaced from the GFCI device along the power cord.