KEYLESS ENTRY APPARATUS

A keyless entry apparatus determines whether a portable apparatus is positioned inside/outside an interface of a vehicle. When an in-vehicle control unit detects that a portable apparatus is positioned in a region which is affected by crosstalk and/or in which saturation occurs, in the vicinities of some of a plurality of transmitting antennas, based on intensity data from some of the plurality of transmitting antennas, the in-vehicle control unit determines whether intensity data from the transmitting antenna is included in a data group composed of a plurality of intensity data that are transmitted from the transmitting antennas and then received by the portable apparatus when the portable apparatus is positioned along the inside of an interface. When it is determined that the intensity data is included/not included in the data group, the in-vehicle control unit determines that the portable apparatus is positioned inside/outside the vehicle.