To provide a laser scanner which is compact, has a wide scanning range, and hardly causes aberrations in laser beam on the plane to be scanned.

The laser scanner (1) is provided with two laser diodes (11a, 11b), a rotating polygon mirror (12), and a scanning lens (13). Laser beams (L1a, L1b) from the two laser diodes are deflected by the rotating polygon mirror, and the plane to be scanned (S) is scanned with the laser beams (L3a, L3b), after passing through the scanning lens. The incident range (R2) of the laser beams (L2a, L2b), after the deflection by the rotating polygon mirror to the scanning lens, can be widened even if the distance (D) from the rotating polygon mirror to the plane to be scanned is made short, so that it is unnecessary to expand the deflection angle of the laser beams (L3a, L3b) with the scanning lens for securing the size of the scanning area (R1).