Provided is a laser device including N semiconductor laser array stacks, a prismatic optical system that shifts optical axes of luminous fluxes respectively output from the N semiconductor laser array stacks so as to decrease intervals among the luminous fluxes, and an imaging optical system that causes the luminous fluxes to be condensed and deflected for each luminous flux. The imaging optical system causes the luminous fluxes to be deflected so that the luminous fluxes overlap each other at a predetermined position and generates a light-condensing point of the luminous fluxes between the imaging optical system and the predetermined position.