widely performed because of their advantage of low NOx emission and low CO2 generation, espe- cially in the case of using natural-gas-based fuel. However, premixed-type combustors tend to gen- erate combustion induced oscillation and, in some cases, this causes serious damage to the combus- tor. Acoustic effects in the combustor and subse- quent equivalence ratio variations seem to play an important role in such combustion oscillation