Input apparatus suitable for portable electronic device

An input apparatus for a portable electronic device capable of detecting the unintentional erroneous input operations and separating the intended correct input operations effectively. The apparatus includes an input unit for allowing a user to enter inputs by a prescribed input operation, an input movement monitoring unit for monitoring a movement of the user at a time of the input operation and a processing unit for processing the inputs entered at the input unit according to the input operation made by the user at the input unit and the movement of the user monitored by the input movement monitoring unit. The apparatus can be adapted to a pen input type electronic device, a slide control type electronic device, and a button control type electronic device. The movement monitored by the input movement monitoring unit can also be utilized as a control command for controlling the operation of the electronic device.