An apparatus for the conveying and inspection of a semi-finished product of the tobacco industry, comprising: - a conveyor with a suction belt configured to hold and convey the semi-finished product along a conveying path, the conveyor comprising at least one guide channel for the semi-finished product, delimited at the sides by two side walls and at the top by a suction belt; - at least one electromagnetic detecting device (20, 40a, 40b) defining at least one detecting channel configured to slidably receive the suction belt and at least one portion of the semi-finished product held on the suction belt, the electromagnetic detecting device (20, 40a, 40b) comprising at least one electromagnetic sensor for detecting at least one property of the semi-finished product and of the suction belt passing through the detecting channel; the conveying apparatus being configured to operate in a first configuration, in which the detecting unit detects at least one property of the suction belt passing through the detecting channel and generates a reference signal, and in a second configuration, in which the detecting unit detects at least one property of the semi-finished product and of the suction belt passing through the detecting channel and generates a measurement signal; the conveying apparatus comprising, or being associated with, a control unit configured to receive and process the measurement signal, correcting or varying the measurement signal as a function of the reference signal so as to obtain an effective measurement data item relating only to the semi-finished product by eliminating from the measurement signal a component due to the suction belt. - a conveyor with a suction belt configured to hold and convey the semi-finished product along a conveying path, the conveyor comprising at least one guide channel for the semi-finished product, delimited at the sides by two side walls and at the top by a suction belt; - at least one electromagnetic detecting device (20, 40a, 40b) defining at least one detecting channel configured to slidably receive the suction belt and at least one portion of the semi-finished product held on the suction belt, the electromagnetic detecting device (20, 40a, 40b) comprising at least one electromagnetic sensor for detecting at least one property of the semi-finished product and of the suction belt passing through the detecting channel; the conveying apparatus being configured to operate in a first configuration, in which the detecting unit detects at least one property of the suction belt passing through the detecting channel and generates a reference signal, and in a second configuration, in which the detecting unit detects at least one property of the semi-finished product and of the suction belt passing through the detecting channel and generates a measurement signal; the conveying apparatus comprising, or being associated with, a control unit configured to receive and process the measurement signal, correcting or varying the measurement signal as a function of the reference signal so as to obtain an effective measurement data item relating only to the semi-finished product by eliminating from the measurement signal a component due to the suction belt.