PURPOSE: To easily and speedily load a tape to a tension measuring terminal with high reproducibility and to enable the measurement with high reliability by executing recording and reproducing operations while adhering the device at the prescribed position of a magnetic recording and reproducing device, and loading the opening/closing type tension measuring terminal from the upside to the tape under travelling.

CONSTITUTION: The recording and reproducing operations are executed while loading the device at the prescribed position of the magnetic recording and reproducing device, and tape tension is measured while loading an opening/ closing type tension measuring terminal 38 from the upside to a tape 5 under travelling. Namely, when the tension measuring terminal 38 falls down, the tension measuring terminal 38 is fixed at a regular height and afterwards, by turning the opening/closing type tension measuring terminal 38 to the closed state, the tape 5 can be loaded to a tension measuring post 38a. Thus, since the tension measuring terminal 38 can be easily and speedily loaded to the tape 5 and the loading is enabled with high reproducibility and without any individual difference, the measurement is enabled with high reliability.