This invention relates to semiconductor laser apparatus with a structure for reducing the divergence angle of output light and for narrowing the spectral width. The semiconductor laser apparatus has at least a semiconductor laser array, a collimator lens, a path rotator, and an optical element with a reflecting function. The collimator lens collimates a plurality of laser beams from the semiconductor laser array, in a predetermined direction. The path rotator outputs each beam collimated in the predetermined direction, with a predetermined divergence angle in the predetermined direction in a state in which a transverse section of the beam is rotated by about 90°. The optical element is arranged at a position where at least a part of each beam from the path rotator arrives, and constitutes at least a part of an external resonator. This optical element reflects a part of each beam from the path rotator to return the reflected part of each beam to the active layer in the semiconductor laser array.