The on-vehicle device control device (10) includes a drowsiness prevention section setting unit (11) that sets a drowsiness prevention zone on the scheduled travel route of the vehicle, a vehicle position acquisition unit (12) that obtains the position of the vehicle, and driving. A drowsiness detection unit (13) for detecting drowsiness of a passenger of the own vehicle different from the driver, and an in-vehicle device control unit (14) for controlling the in-vehicle device (30). If the drowsiness of the occupant is detected when the position of the host vehicle is within the drowsiness prevention section, the on-vehicle device control unit (14) controls the on-vehicle device (30) so as to wake up. When the drowsiness of the occupant is detected when the position of the host vehicle is outside the dozing prevention section, the in-vehicle device control unit (14) controls the in-vehicle device (30) so as to promote the drowsiness.車載機器制御装置（１０）は、自車両の走行予定経路上に居眠り防止区間を設定する居眠り防止区間設定部（１１）と、自車両の位置を取得する車両位置取得部（１２）と、運転者とは異なる自車両の搭乗者の眠気を検知する眠気検知部（１３）と、車載機器（３０）を制御する車載機器制御部（１４）とを備える。自車両の位置が居眠り防止区間内のときに搭乗者の眠気が検知された場合、車載機器制御部（１４）は、その眠気を覚ますように車載機器（３０）を制御する。自車両の位置が居眠り防止区間外のときに搭乗者の眠気が検知された場合、車載機器制御部（１４）は、その眠気を助長するように車載機器（３０）を制御する。
