This paper investigates whether ChatGPT, a large-scale language model (LLM), can support formal software verification by generating loop invariants. We utilize ChatGPT to generate loop invariants for 106 C programs, and verify the validity and usability of the generated invariants using Frama-C and CPAchecker. Our results demonstrate that ChatGPT generates valid and useful invariants, enabling verification of tasks previously unsolved by Frama-C.