<p>Disclosed is a coordinate input apparatus for detecting an input vibration from a vibration pen by a vibration sensor provided on a vibration transmitting plate to measure a vibration transmission time to the vibration pen to detect the input coordinates of the vibration pen on the vibration transmitting plate on the basis of the measurement result. The vibration pen is made wireless by incorporating all mechanisms required to generate the vibration. A drive timing for vibration input from the vibration pen and used as a measurement origin of the vibration transmission time is transmitted to a main body for performing the coordinate detection processing by bringing the vibration pen in temporary contact with the main body. <IMAGE></p>
