Interdigitated Array (IDA) Electrodes have attracted significant attention in biochemical sensing, trace electroanalysis and so on. It can be used for investigating molecule at very low concentration (0.01 mM) or reaction intermediates with short lifetime (millisecond). Our group fabricates the carbon-carbon IDA and carbon-platinum IDA for application in various reactions like electrocatalytic proton reduction reaction and especially it can be used for H₂ detection.