Disclosed is a method for detecting false alarm. The method includes receiving a measured value that is measured when an alarm is generated from a target for monitoring, measuring non-similarity between the measured value that is measured when the alarm is generated and a pre-stored normal pattern, measuring non-similarity between the measured value and pre-stored measured values related to a past false alarm if the non-similarity exceeds a predetermined threshold value and providing the generated alarm to a user if the non-similarity between the measure value and the pre-stored related values related to the past false alarm exceeds the predetermined threshold value.