To provide a testing method and a testing means for simultaneous, simple reference by accurately grasping the position of each mast by a highly reliable method in the process of the installation safety test of the mast.

In the mast strength-testing means utilizing a traveling testing device 1 that has force units 2 and 4 for applying a bending load to the mast 3 and receives data for indicating the behavior of the mast 3 by them, the traveling testing device 1 is provided with a DGPS receiver comprising a GPS receiver for receiving a GPS signal 6 and a VHF receiver for receiving correction data 12 is provided, thus transmitting the signal of the DGPS receiver for indicating the position of the mast to a digital data memory. More specifically, a design is added, where the position of the mask is measured and referred to by utilizing the GPS before and after the execution of a test.