The present invention relates to a side mirror for an automobile, and more particularly, to a side mirror for an automobile in which an assembled structure is modified such that even in case of an excessive pressing the side mirror to fall in a driver's view, in comparing with pressing a mirror for adjusting to fall in a driver' view as a conventional method, the assembled state is not return to a disassembled state. In accordance with the present invention, an assembly work is easily preformed and further a assemble state is not easily return to a disassemble state by an external force.