A sunroof apparatus including a front panel and a rear panel closing a roof opening, having a slider coupling mechanism interlocking between a front slider actuating the front panel and a rear slider actuating the rear panel while achieving a simplified structure and compacted size thereof with its number of parts reduced. The coupling arm is swingably pivotally supported by the rear slider, and the coupling arm is provided with a stopper for regulating the back-and-forth movement of the rear slider by fitting to a locking hole formed in the guide rail, and the front slider is provided with a coupling pin and the coupling arm is provided with a coupling cam groove, and the front slider is moved backward so that the coupling pin and the coupling cam groove are engaged with each other to thereby swing the coupling arm so that the stopper is disengaged from the locking hole and the rear slider being interlocked with the front slider is rendered to be moved back and forth.