A variable valve unit for an internal combustion engine includes a first arm opening and closing a valve, a second arm driven by a cam, a third arm receiving a displacement of the second arm to drive the first arm, and a variable mechanism displacing the fulcrum of the second arm. The second arm has a drive plane. The third arm has a shaft member formed with a driven surface contacting with the drive plane. The displacement of the second arm is transmitted to the third arm with sliding between the driven surface and the drive plane.