A roof apparatus comprising: a movable panel for opening and closing an opening portion provided at a roof portion of a vehicle; a guide rail configured to be provided at an edge portion of the opening portion in a vehicle width direction and arranged to be extended in a vehicle front/rear direction; a first rail portion and a second rail portion which are provided at the guide rail in a manner that at least a part of the first rail portion and at least a part of the second rail portion are overlapped with each other in the vehicle width direction, the second rail portion being arranged above the first rail portion in a vehicle height direction; a front side guide member provided at a front end portion of the guide rail and including a guide groove which is inclined in a vehicle upward direction towards the vehicle rear direction and is connected to the second rail portion at a rear end of the guide groove; a front side link member including a support protruding portion which is movable along the second rail portion or along the guide groove, the front side link member being connected to a front portion of the movable panel; and a transmission member which is movable along the first rail portion, and is linked to a rear side link member connected to a rear portion of the movable panel and is linked to the front side link member, the transmission member being arranged to be extended in the vehicle rear direction and being drivably connected to an electric drive source, wherein the support protruding portion of the front side link member moves up the guide groove of the front side guide member and then enters the second rail portion, the transmission member is supported at the first rail portion to be slidable in the front/rear direction, the transmission member, in a fully-closed state of the movable panel, causes the movable panel to be in a tilt-up state by moving the rear portion of the movable panel upwardly relative to the support protruding portion which is positioned at the guide groove and serves as a fulcrum point of the movement of the movable panel in a case where the rear side link member moves in association with a movement of the transmission member in the vehicle rear direction, the transmission member causes the movable panel to be in a pop-up state by moving the front portion of the movable panel upwardly into a case where the support protruding portion enters from the guide groove in the second rail portion in association with the movement of the transmission member further in the vehicle rear direction, and the transmission member causes the movable panel to perform a sliding movement while the movable panel remains in the pop-up state. a movable panel for opening and closing an opening portion provided at a roof portion of a vehicle; a guide rail configured to be provided at an edge portion of the opening portion in a vehicle width direction and arranged to be extended in a vehicle front/rear direction; a first rail portion and a second rail portion which are provided at the guide rail in a manner that at least a part of the first rail portion and at least a part of the second rail portion are overlapped with each other in the vehicle width direction, the second rail portion being arranged above the first rail portion in a vehicle height direction; a front side guide member provided at a front end portion of the guide rail and including a guide groove which is inclined in a vehicle upward direction towards the vehicle rear direction and is connected to the second rail portion at a rear end of the guide groove; a front side link member including a support protruding portion which is movable along the second rail portion or along the guide groove, the front side link member being connected to a front portion of the movable panel; and a transmission member which is movable along the first rail portion, and is linked to a rear side link member connected to a rear portion of the movable panel and is linked to the front side link member, the transmission member being arranged to be extended in the vehicle rear direction and being drivably connected to an electric drive source, wherein the support protruding portion of the front side link member moves up the guide groove of the front side guide member and then enters the second rail portion, the transmission member is supported at the first rail portion to be slidable in the front/rear direction, the transmission member, in a fully-closed state of the movable panel, causes the movable panel to be in a tilt-up state by moving the rear portion of the movable panel upwardly relative to the support protruding portion which is positioned at the guide groove and serves as a fulcrum point of the movement of the movable panel in a case where the rear side link member moves in association with a movement of the transmission member in the vehicle rear direction, the transmission member causes the movable panel to be in a pop-up state by moving the front portion of the movable panel upwardly into a case where the support protruding portion enters from the guide groove in the second rail portion in association with the movement of the transmission member further in the vehicle rear direction, and the transmission member causes the movable panel to perform a sliding movement while the movable panel remains in the pop-up state.