A sound focus speaker adopting a gas-filled sound lens enhances efficiency of transferring sound from a source to target area and of protecting a spread of transferred sound. The sound focus speaker includes a gas-filled sound lens, sound sources for generating sound and a sound-absorption room for surrounding the sound lens and the sound sources. Sound emitted from the sound focus speaker is focused at specific distance to make a focus point and not spread to the outer of the focus point from forming a sound area.