ANALOG INPUT AND OUTPUT CIRCUIT AND VACUUM PROCESSING APPARATUS

The invention provides an analog input and output circuit and a vacuum processing apparatus capable of automatically performing the correction of all analog inputs and outputs via a single reference voltage adjustment, thereby solving the prior art problem of requiring a different correction value for each channel for accurately controlling the analog input and output due to the difference in the on resistances of switches for respective channels of an analog multiplexer. The prevent invention comprises an A/D converter 505 for converting an input analog signal into a digital signal; a D/A converter 506 for converting the digital signal into an analog signal; a computing unit for computing a first correction value 604 with respect to a digital signal of the input signal from the A/D converter and a second correction value 606 with respect to a digital signal output to the D/A converter using the first correction value; and a control unit for outputting control signals from the D/A converter 506 using the first correction value 610 and the second correction value 612.