An in-vehicle device includes: a hard disk drive for storing data; a communication element for transmitting a message to an user; an input element for receiving an instruction from the user; a communication control element for obtaining altitude information; and an activation control element for controlling activation of the hard disk drive. The communication control element obtains the altitude information before the hard disk drive is activated when the in-vehicle device is activated for the first time since standby power supply stopped while the in-vehicle device was not activated. The communication control element transmits the message when the current position is equal to or higher than a predetermined altitude. The activation control element starts to read the data from the hard disk drive when the input element receives the instruction that the user permits the activation of the hard disk drive.