A sunroof driving device includes a pair of rail members adapted to be arranged at both edges of a roof opening formed in a vehicle roof in a vehicle width direction and each extending along a vehicle longitudinal direction, a slide member slidably supported by each of the rail members in a longitudinal direction therof, a supporting member connected to the slide member and supporting a movable panel opening and closing the roof opening, a cross-connecting member extending along the vehicle width direction for establishing connection between respective front ends of the rail members, a drive motor arranged at the cross-connecting member and including a rotating shaft extending along the cross-connecting member, a torque wire extending along the cross-connecting member and integrally rotating with the rotating shaft, and a torque-transmitting member rotated by the torque wire and sliding the slide member along each of the rail members.