An error diagnosing method performed by an apparatus for diagnosing an error of operating equipment in a smart farm includes: receiving a control message which triggers an error diagnosis; analyzing data collected from a smart farm on the basis of a preset error diagnostic rule when the control message is received; outputting a result of determining whether an error of the operating equipment installed in the smart farm occurs according to an analysis result; and providing the error determination result to a user through a user interface. It is possible to stably operate and efficiently manage a smart farm.