Pallet detection device that acquires point cloud data indicating a point cloud measured by a two-dimensional distance measurement device on a depth map; detects a straight line corresponding to a front surface of a pallet based on the point cloud in a region presumed to include the front surface of the pallet in the point cloud data; detects a line segment indicating the front surface of the pallet based on the straight line; acquires position and orientation of the pallet based on the line segment. Acquires one or more straight line candidates and assigns for each of the one or more straight line candidates a score to the point cloud and selects the straight line from the one or more straight line candidates based on a score accumulated value obtained by accumulating the score for the point cloud in the region presumed to include the front surface of the pallet.