We propose and demonstrate two types of narrowband multi-channel filters: transmittance-integrated narrow-bandpass filter arrays and reflectance narrowband multi-channel filters. We develop a combinatorial etching technique possessing 32 elements on a single substrate with which to fabricate these integrated narrow bandpass filters. Double-chamber integrated optical filter arrays are fabricated by use of this etching technique. Reflectance can be achieved by combining metal and dielectric materials. These narrowband multi-channel filters and narrow bandpass filter arrays show good filtering features and can be utilized in many optical applications.