An angle-adjustable hinge provided with a first arm having a case portion and a second arm connected to the first arm with the case portion as to oscillate around a first axis and having a gear portion. The angle-adjustable hinge is also provided with a wedge-shaped window portion formed on the case portion of the first arm and a floating wedge member, disposed as to move within the wedge-shaped window portion, having one face side as a toothed face to engage with the gear portion and another face side as a contact face to contact a wedge face on an outer side of the wedge-shaped window portion.