The moisture meter determines the relative moisture content between the two metal pins on the surface of the measured object. Statements on the total moisture content of, for example, a brick cannot be derived from this, as only a measurement on the surface takes place. In this case, a higher moisture content and thus a higher conductivity between the pins leads to a higher percentage display. The percentage display can be used, for example, to determine whether different degrees of moisture prevail at different points on a wall, so that a possible damp spot or leak can be detected. The measuring accuracy of the moisture detector is +/- 3%.