An E-meter is an electronic device manufactured at the Church of Scientology's Golden Era Productions facility, and is used exclusively by the Church. The device is a variation on an ohmmeter, using a Wheatstone bridge to measure electrical resistance. It is used as an aid by Dianetics and Scientology counselors and counselors-in-training in some forms of auditing, the application of the techniques of Dianetics and Scientology to another or to oneself for the express purpose of addressing spiritual issues. The device is formally known as the Hubbard Electrometer , for the Church's founder, L. Ron Hubbard.

The Church of Scientology restricts the use of the E-meter to trained professionals, treating it as "a religious artifact which can only be used by Scientology ministers or ministers-in-training. It does not diagnose or cure anything. It purports to measure the mental state or change of state of a person and thus is of benefit to the auditor in helping the preclear locate areas to be handled."