We propose a new process of fabricating nano-gap electrode pairs using an atomic-layer-deposited (ALD) thin film as a sacrificial layer. In this technique, we can control the width of a gap precisely by varying the number of deposition cycles of the ALD layer, and produce many identical gaps simultaneously. Using ALD Al2O3 as a sacrificial layer, we have fabricated poly-Si/Au nano-gaps of 10 nm width successfully. This new approach can provide a useful tool for the massive production of integrated molecular device circuits.