The present invention has an object to provide an information processing apparatus and authentication program storage medium which can prevent unauthorized use reliably at low costs. The information processing apparatus has a connection section to which a device is removably connected and performs information processing using the device connected to the connection section. It is equipped with a condition setting section which establishes insertion/removal conditions for a device inserted into the connection section; and an authentication section which determines upon start-up of the information processing apparatus whether insertion/removal of a device satisfies the insertion/removal conditions established by the condition setting sections, and permits the information processing apparatus to perform information processing if it is determined that the insertion/removal satisfies the established insertion/removal conditions.