PURPOSE: To evaluate a motion technique by receiving a signal transmitted from a ball containing a transmitting device by a receiving device provided separately, and executing the calculation of the number of times, a calculation of a mark obtained, etc.

CONSTITUTION: A ball 2 side electric circuit 1 consists of a pressure sensor 4, an amplifying circuit 5 for amplifying its detecting signal, a transmitting circuit 6 for transmitting this output, and an antenna 7. On the other hand, a receiver side circuit part 3 is provided with a receiving antenna 8, and a buzzar 13 for amplifying a signal from a receiving circuit 9, executing a prescribed operation processing 11, displaying 12 its output, and generating a prescribed informing sound basing on an output. In this state, basing on a detecting signal transmitted from the transmitting device, a numerical information signal related to the external force applied to the ball is received by the receiving device, the numerical information signal related to the external force is calculated, and the number of times of football and the marks obtained are displayed, respectively.