A fixing device (20) for securing an antenna (10) to a front panel (60) of a computer enclosure (80), includes a main body (22), two fixing arms (24) extending from opposite ends of the main body, and two locking arms (30) extending from the main body and perpendicular to the fixing arms. Two position posts (23) and two pairs of hooks (42) are formed from the main body and engage in corresponding position holes (62) and mounting holes (64) of the panel. Two aligned slots (26) are defined in the fixing arms for receiving the antenna. Each locking arm includes a connecting portion (32) and a bent portion (34). Each locking arm can rotate around a rotation section (31) of the connecting portion, and a locking hole (38) of the bent portion can engage with a locking block (28) of the fixing arm thereby securing the antenna in the slots.