Abstract
A retaining mechanism consists of a seat including a curved support portion connected to a coupling portion for extending through an engaging slot on a substrate, and a clamp member slidably assembled to the seat. The coupling portion has an end provided with a retaining protrusion for protruding into a first end of the engaging slot and another end forming an elastic clamping section pressing on a bottom of the substrate. The seat further includes a holding section located corresponding to the retaining protrusion and a pressing section of the clamp member, so that a clamping opening is formed between the pressing section and the holding section for clamping an electronic card thereto. The holding section has a beveled outer edge retreated toward the support portion and the coupling portion to allow observation of the engagement of the retaining protrusion with the engaging slot from a top of the substrate.