A spoofing detection device comprising: facial image sequence acquisition means that acquires a facial image sequence indicating a user's face; line-of-sight change detection means that detects information about temporal line-of-sight change from the facial image sequence; presentation information display means that displays presentation information presented to the user as part of authentication processing; and spoofing determination means that determines a likelihood that a face indicated by the facial image sequence is spoofing, in accordance with the information about temporal line-of-sight change with respect to the presentation information, wherein the presentation information includes first presentation information and second presentation information that is different from the first presentation information, the first presentation information and the second presentation information being textual information indicating steps of the authentication processing, the presentation information display means is configured to display the first presentation information at a first position, and switch the first presentation information to the second presentation information at a timing, the second presentation information being displayed at a second position that is different from the first position, and the spoofing determination means is configured to determine a likelihood of the spoofing by comparing the information about temporal line-of-sight change with the timing of switching from the first presentation information to the second presentation information and change from the first position to the second position in accordance with the switching. facial image sequence acquisition means that acquires a facial image sequence indicating a user's face; line-of-sight change detection means that detects information about temporal line-of-sight change from the facial image sequence; presentation information display means that displays presentation information presented to the user as part of authentication processing; and spoofing determination means that determines a likelihood that a face indicated by the facial image sequence is spoofing, in accordance with the information about temporal line-of-sight change with respect to the presentation information, wherein the presentation information includes first presentation information and second presentation information that is different from the first presentation information, the first presentation information and the second presentation information being textual information indicating steps of the authentication processing, the presentation information display means is configured to display the first presentation information at a first position, and switch the first presentation information to the second presentation information at a timing, the second presentation information being displayed at a second position that is different from the first position, and the spoofing determination means is configured to determine a likelihood of the spoofing by comparing the information about temporal line-of-sight change with the timing of switching from the first presentation information to the second presentation information and change from the first position to the second position in accordance with the switching.