A thin hinge includes a holding seat, an arc-shaped driven member and a torsional force generation assembly. The holding seat includes a base, a housing space and a linear slide track. The arc-shaped driven member is located in the housing space and includes an operational portion, a curved portion connected to the operational portion and a driving portion extended from the curved portion toward the operational portion to couple with the assembly portion. The torsional force generation assembly includes at least one driving arm connected to the arc-shaped driven member, a slide seat connected to the driving arm and located in the housing space corresponding to the linear slide track, a detent plate located at another side of the linear slide track facing the housing space and corresponding to the slide seat, and at least one torsional spring coupled with the slide seat and the detent plate.