A vehicular sunroof apparatus includes a front panel, a rear panel, a linking rod, a rod-locking part, and a slider linking part. The linking rod is connected to a rear slider provided for opening the rear panel. The rod-locking part is disposed on a vehicle roof for locking a distal end of the linking rod when the rear panel is in a fully closed state. The slider linking part is provided on a front slider provided for opening/closing the front panel. The slider linking part is designed to engage with the distal end part and to release the distal end part from the locking engagement with the rod-locking part when the front slider moves from a fully closed position to a half-open position.