Device for detecting alcohol in a gas sample, in particular in exhaled respiratory air, wherein the device comprises - a measuring chamber for receiving a gas sample, - a first IR radiation source, - a second IR radiation source, - a first IR detector, - a second IR detector and - a signal-processing evaluation unit, wherein a respective mirror (5, 6) is arranged on each of two opposite walls of the measuring chamber, wherein the two IR detectors (9, 13) are arranged on the two opposing walls (5, 6) of the measuring chamber, wherein each of the two IR radiation sources (7, 11) is designed to emit a respective IR beam into the measuring chamber, wherein each of the two IR detectors (9, 13) is designed to generate at least one measurement value on the basis of an incident IR beam, wherein the device is designed such that - an IR beam from the first IR radiation source passes through the measuring chamber and strikes the first IR detector and - an IR beam from the second IR radiation source passes through the measuring chamber and strikes the second IR detector, wherein the device is designed such that - an IR beam emitted by the first IR radiation source is reflected at least once, preferably multiple times, by at least one mirror (5, 6), before said IR beam strikes the first IR detector and - an IR beam emitted by the second IR radiation source is reflected at least once, preferably multiple times, by at least one mirror (5, 6), before said IR beam strikes the second IR detector, and wherein the evaluation unit is designed - to automatically decide whether or not a gas sample in the measuring chamber contains alcohol and - to make this decision using measurement values which the two IR detectors (9, 13) generated while a gas sample to be examined is situated in the measuring chamber. wherein the device comprises - a measuring chamber for receiving a gas sample, - a first IR radiation source, - a second IR radiation source, - a first IR detector, - a second IR detector and - a signal-processing evaluation unit, - a measuring chamber for receiving a gas sample, - a first IR radiation source, - a second IR radiation source, - a first IR detector, - a second IR detector and - a signal-processing evaluation unit, wherein a respective mirror (5, 6) is arranged on each of two opposite walls of the measuring chamber, wherein the two IR detectors (9, 13) are arranged on the two opposing walls (5, 6) of the measuring chamber, wherein each of the two IR radiation sources (7, 11) is designed to emit a respective IR beam into the measuring chamber, wherein each of the two IR detectors (9, 13) is designed to generate at least one measurement value on the basis of an incident IR beam, wherein the device is designed such that - an IR beam from the first IR radiation source passes through the measuring chamber and strikes the first IR detector and - an IR beam from the second IR radiation source passes through the measuring chamber and strikes the second IR detector, - an IR beam from the first IR radiation source passes through the measuring chamber and strikes the first IR detector and - an IR beam from the second IR radiation source passes through the measuring chamber and strikes the second IR detector, wherein the device is designed such that - an IR beam emitted by the first IR radiation source is reflected at least once, preferably multiple times, by at least one mirror (5, 6), before said IR beam strikes the first IR detector and - an IR beam emitted by the second IR radiation source is reflected at least once, preferably multiple times, by at least one mirror (5, 6), before said IR beam strikes the second IR detector, and - an IR beam emitted by the first IR radiation source is reflected at least once, preferably multiple times, by at least one mirror (5, 6), before said IR beam strikes the first IR detector and - an IR beam emitted by the second IR radiation source is reflected at least once, preferably multiple times, by at least one mirror (5, 6), before said IR beam strikes the second IR detector, and wherein the evaluation unit is designed - to automatically decide whether or not a gas sample in the measuring chamber contains alcohol and - to make this decision using measurement values which the two IR detectors (9, 13) generated while a gas sample to be examined is situated in the measuring chamber. - to automatically decide whether or not a gas sample in the measuring chamber contains alcohol and - to make this decision using measurement values which the two IR detectors (9, 13) generated while a gas sample to be examined is situated in the measuring chamber.