A sight-line end estimation device (1) includes a sight-line direction detection portion (2) that detects a sight-line direction of a driver of a vehicle, a target object detection portion (4, 5) that detects the positions of target objects existing around the vehicle, a relative position acquisition portion (7) that acquires relative positional information between the driver and the target object detection portion, and a sight-line end estimation portion that estimates the driver's sight-line end by detecting a target object whose position detected by the target object detection portion lies substantially in the driver's sight-line direction detected by the sight-line direction detection portion.