A photonic crystal, which is a periodically arranged structure made of free-standing columns, has a base material of at least one metal or a metal alloy. Intermediate spaces between the columns allow passage of a gas to be analyzed. The photonic crystal has predefined imperfections, by which at least one resonator is formed, the resonant frequency of which is in a frequency range which is absorbed by a gas component to be detected. A heating unit heats at least some of the columns and at least one detector element extracts the energy present in the resonator in the heated state under the action of the gas to be analyzed. The device may have extremely small dimensions and very low energy consumption.