To project a rectangular laser spot having a predetermined size and a high laser power density onto the surface of an object, a semiconductor manufacturing apparatus comprises a control unit for controlling power of a laser light source, an optical waveguide unit (1) including a core section (10) transmitting laser light and a clad section (11) covering the core section (10), and a lens (3) for forming the laser light output through the optical waveguide unit (1) into a laser spot having a predetermined shape, an output end surface (15) of the core section (10) has a rectangular shape with one side length of 1 μm to 20 μm and the other side length of 1 mm to 60 mm, and the laser source is set to make the power density of the laser spot output from the core section (10) to be 0.1 mW/μm2 or more.