回複：請教老貓或其它懂法律的高手一個關於合同的問題，謝謝！

Read both contracts, the one the previous signed with the ATM company, and the one you signed for purchasing the store, carefully, to figure out what your responsibilities are.

Without such information, I would assume that the previous owner assigned rights and delegated duty to you for the ATM machine, so that you should have the same rights and liabilities of the owner. The other possibility is that the owner made a novation with the ATM for you to substitute him in the contract. Either way, unless the ATM materially breached the contract, you must perform. From what you said, I don't think failure to maintain the machine amounts to a material breach. You may sue the ATM for reliance damage and expectation damage.

There is a small possibility that you can rescind the contract. That is, when the owner delegated the duty to you but you did not expressly assume the duty. Again, that requires careful reading of the contracts.