Abstract: A telemeter apparatus for counting a heart rate is provided which can accurately measure a heart beat signal without being affected by a radio interference between adjacent exercise test systems. A telemeter apparatus for counting a heart rate has: a transmitter unit to be attached to a subject using an exercise test system and for transmitting from a transmitting coil a heart beat signal detected from the subject, in the form of a magnetic signal; receiving coils respectively disposed at the both sides of a body of the exercise test system, and for receiving the magnetic signal transmitted from the transmitting coil; comparators for accepting the received signal from the corresponding receiving coil which has been amplified and rectified, and for comparing the accepted signal with a predetermined threshold level; an AND circuit to which output signals from the comparators are input; and a heart rate display unit for displaying a heart rate on the basis of an output signal from the AND circuit.