An attachment mechanism for fastening an electronic component includes a circuit board and a fastener. The circuit board includes a first connector to be connected to a second connector of the electronic component. The first connector defines a groove in a first end of the first connector and a hooking slot below the groove. The fastener includes a main body and an operation portion extending up from the main body. The main body includes a block engaging in the groove and a latch engaging in the hooking slot. An engaging bar protrudes from the operation portion to abut against a top of the electronic component.