Department of Industrial Engineering, Seoul National University of Science and Technology, Seoul 139-743, Korea(Received April 28, 2014; Revised May 16, 2014; Accepted May 20, 2014)Abstract: Five factors are identified, which affect the performance of optical filter: 1) type of optical glass, 2) existence of Fe, 3) photo pic coating type, 4) coating form, and 5) coating thickness. If we consider all the levels of five factors, there are 360 possible candidates. We determined five evaluation criteria, which can be used to evaluate possible candidates. For the performance measures we selected white-state avearge voltage, black-state average voltage, and black-state error rate. And we added economic criterion and quality and maintenance criterion. Through the two-step statistical analysis of white-state avearge voltage, black-state average voltage, and black-state error rates, we selected final four candidates. Based on the five criteria we finally determined optimal optical filter using AHP.Keywords: Delphi, AHP (analytic hierarchy process), Black voltage, White voltage, HEA (high efficiency), VLR (value low reflector), VLRW (value low reflector wide)