Oxidation of benzene to phenol with nitrous oxide being an untypical reaction for zeolite catalysis arouses a great interest among researchers. Several hypotheses concerning reaction mechanism are discussed. Some of them assume a key role of the Bronsted acid centers (BAC), though few experimental support for this idea is available. The goal of this work is to study the Bronsted acidity of FeZSM-5 zeolite catalyst (0.13 wt.% Fe2O3) to reveal a relationship (if any) between the BAC concentration and the catalytic activity in benzene oxidation. Various pretreatments of the sample including a high-temperature calcination up to 900 degrees C were used to vary the BAC concentration, which was measured by infrared spectrometry. No evidence of the Bronsted acidity importance for catalyzing the reaction was found. What is more, a formal inverse correlation was discovered. Thus, a manifold decrease in BAC concentration was accompanied by a remarkable increase in the oxidation rate, with a small acid recreation under the reaction conditions used. The obtained results support an earlier suggested redox mechanism of the reaction involving a special oxygen form produced at N2O decomposition on Fe-containing active sites.