PURPOSE: To easily search a golf ball by burying a power source-less transponder in the golf ball, and providing the transponder with a detector for transmitting a question radiowave and receiving its response radiowave, thereby searching the position of the corresponding search ball

CONSTITUTION: When a golf ball 11 stroked into a bush, a detector 9 is first inserted to the vicinity of the bush to which the golf ball 11 is stroked. A question signal is generated from the antenna control circuit 6 of a question device 5 in the detector 9, and this is transmitted from an antenna 8 to the golf ball 11 through a transmitter-receiver circuit 7 as radiowave. Successively, a response radiowave is generated from a transponder 10 integrated into the golf ball 11, and this is received by the antenna 8 and inputted to the received data demodulating converting circuit 4 of a controller 1. Consequently, when this golf ball 11 is the corresponding search ball, a voice generator or light emitter 2 is operated by a ball search signal generating circuit 3 to inform a searcher of the position of the golf ball 11.