Laser surveying device

A laser surveying device includes a rotatable and tiltable laser head in a housing to rotate about a rotational axis set in a certain direction and project a laser beam around and a tilt angle detector to detect a tilt angle of the laser head relative to the housing. The tilt angle detector includes a pattern plate on which a certain pattern is formed, provided in one of the laser head and the housing, light receiving elements arranged in the other of the laser head and the housing at different positions opposite to positions of the pattern plate to receive light beams reflected by the pattern plate, and a determiner to determine a direction and an amount of tilt of the laser head on the basis of a light receiving amount of each of the light receiving elements.