To provide a laser exposure apparatus and an image forming apparatus which, even when one of beam detection parts is in trouble, continue scanning by making use of the rest of the detection parts.

The laser exposure apparatus for an image forming apparatus includes: an emission part which emits laser; a movable mirror which reciprocally rocks for reflecting the emitted laser to reciprocally scan the face to be irradiated of an object to be irradiated; a first beam detection part which detects that the irradiation position of the reciprocally scanning laser is on a beginning reference of scanning in a forward stroke and outputs a first detection signal; a second beam detection part which detects that the irradiation position of the reciprocally scanning laser is on a beginning reference of scanning in backward stroke and outputs a second detection signal; and an emission control part which controls the laser emission from the emission part on the basis of the first and the second detection signals and allows the face to be irradiated exposed with a predetermined pattern. The laser exposure apparatus for the image forming apparatus is characterized in that the emission control part controls the laser emission so as to emit the laser only for scanning in the backward stroke but not to emit the laser in scanning in the forward stroke when abnormality is detected in the first detection signal and the second detection signal is normal.