Abstract: A boundary position search method and an information recording apparatus are provided for rapidly transferring a recording/reproducing head to a boundary position between a recorded region and an unrecorded region of a recording disc when new information data is recorded on the recording disc. In response to a recording start instruction, the recording/reproducing head is first forcedly transferred in a radial direction of the disc, while confirmation is made as to the presence or absence of an RF signal carrying an information signal in a read signal. A slider unit is controlled to stop a transfer operation of the recording/reproducing head when a transition is detected from a state in which an RF signal exists to a state in which no RF signal exists.