A watch intended to be removably mounted on a support, including a watch case and an independent removable attachment device arranged to retain the watch case in an opening provided in the support, the watch case including an upper portion, on the dial side, and a lower portion including a back cover, the lower portion being arranged to be housed inside the opening in the support and being of smaller dimensions than those of the upper portion to form a flat peripheral shoulder. The attachment device includes a flange having a central opening arranged to receive the lower portion of the watch case and an inner rim delimiting the central opening, the inner rim being arranged to be housed inside the opening in the support. The inner rim includes a locking device for locking the attachment device on the lower portion of the watch case.

A wearable electronic device including a body having a first locking recess, a wearable element having a second locking recess and a locking structure disposed in one of the first and the second locking recesses and including a pressing element and a locking element connected with each other is provided. The locking element is adapted to lock another one of the first locking recess and the second locking recess to assemble the body and the wearable element together, and the pressing element is adapted to receive an external force and move along a vertical axial direction into the first locking recess or the second locking recess which the locking structure is located, and drive the locking element to move along a horizontal axial direction into the first locking recess or the second locking recess which the locking structure is located, so as to unlock the body and the wearable element.