A secure device for a heat sink and CPU includes a main support arm and an operation handler. The main support arm has a first hook section at one end thereof and provides a contact face and a movable second hook section at another end thereof. The operation handle further includes a main operation part and a handle part and the main operation part provides a guide groove with a first end and a second end. The guide groove extends along radial direction of main operation part from the first end to the second end and a uvula is formed between the first end and the second end. The circumferential side of the main operation part defines a press section for touching the contact face and a pivotal shaft is movably joined to the guide groove and the second hook section to actuate the second hook section moving upward or downward to selectively perform engagement or loosening while the pivotal shaft moving along the guide groove between the first and second ends.