Method for detecting a fault in an electrical enclosure comprising at least one electrical equipment item (11, 12) and at least one volatile organic compounds sensor, at least one microparticles sensor, at least one gas sensor, said method cyclically comprising over time: - measuring at least one climate parameter in the electrical enclosure; - measuring a concentration of volatile organic compounds (MES COV); - measuring a concentration of gases (MES gas); - measuring a concentration of microparticles (MES par); - correcting (220, 320, 420) the measurements of the concentration of volatile organic compounds (MES COV), of gases (MES gas) and of microparticles (MES par) on the basis of the at least one climate parameter; - calculating (250, 350, 450) a drift of concentration of volatile organic compounds (DR COV), of gases (DR gas) and of microparticles (DR par) on the basis of time; - comparing (260, 360, 460) the drift of concentration of volatile organic compounds (DR COV), of gases (DR gas) and of microparticles (DR par), respectively, to a predefined drift of concentration threshold of volatile organic compounds (SD COV), of gases (SD gas) and of microparticles (SD par); - calculating (270, 370, 470) a change of concentration of volatile organic compounds (EV COV), of gases (EV gas) and of microparticles (EV par); - comparing (280, 380, 480) the change of concentration of volatile organic compounds (EV COV), of gases (EV gas) and of microparticles (EV par), respectively, to a predefined change of concentration threshold of volatile organic compounds (SEvoc), of gases (SE gas) and of microparticles (SE par); - emitting an alarm when: - the drift of concentration threshold of microparticles (SD par) or the change of concentration threshold of microparticles (EV par) is exceeded; and when - at least one drift of concentration threshold or one change of concentration threshold of volatile organic compounds (SD VOC, EV VOC) or of gases (SD gas, EV gas) is exceeded. - measuring at least one climate parameter in the electrical enclosure; - measuring a concentration of volatile organic compounds (MES COV); - measuring a concentration of gases (MES gas); - measuring a concentration of microparticles (MES par); - correcting (220, 320, 420) the measurements of the concentration of volatile organic compounds (MES COV), of gases (MES gas) and of microparticles (MES par) on the basis of the at least one climate parameter; - calculating (250, 350, 450) a drift of concentration of volatile organic compounds (DR COV), of gases (DR gas) and of microparticles (DR par) on the basis of time; - comparing (260, 360, 460) the drift of concentration of volatile organic compounds (DR COV), of gases (DR gas) and of microparticles (DR par), respectively, to a predefined drift of concentration threshold of volatile organic compounds (SD COV), of gases (SD gas) and of microparticles (SD par); - calculating (270, 370, 470) a change of concentration of volatile organic compounds (EV COV), of gases (EV gas) and of microparticles (EV par); - comparing (280, 380, 480) the change of concentration of volatile organic compounds (EV COV), of gases (EV gas) and of microparticles (EV par), respectively, to a predefined change of concentration threshold of volatile organic compounds (SEvoc), of gases (SE gas) and of microparticles (SE par); - emitting an alarm when: - the drift of concentration threshold of microparticles (SD par) or the change of concentration threshold of microparticles (EV par) is exceeded; and when - at least one drift of concentration threshold or one change of concentration threshold of volatile organic compounds (SD VOC, EV VOC) or of gases (SD gas, EV gas) is exceeded.