The rotors of electric motors can be well balanced in mass production, thus reducing the forces and consequently vibrations and noise. A very good mass balance results in the expression of other forces, such as the problem of unbalanced magnetic pull. The minimised mass imbalance causes the previously relatively small forces, such as unbalanced magnetic pull, to become more pronouced. In order to measure and evaluate the unbalanced magnetic pull, a device capable of measuring its impact had to be constructed. This thesis describes the design and construction of said measuring device. Some test measurements were subsequently preformend and analysed. The constructed device enables the measurements caused by unbalanced magnetic pull in small electric motors.