According to one embodiment, a laser processing device includes a light irradiation section, and an optical element. The optical element includes a first transparent member provided via a gap with a tip of the light irradiation section, and a second transparent member. The first transparent member includes a first surface opposed to the tip of the light irradiation section, and a second surface provided so as to be connected to the first surface. The second transparent member includes a flat surface and a convex surface, the flat surface being provided so as to be opposed to the second surface of the first transparent member, the light passed through the first transparent member passing through the convex surface. An optical axis of the laser beam passing through the first surface and an optical axis passing through the convex surface are different from each other.
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