This paper proposes two novel approaches to address the Limitations problem of Retrieval-Augmented Generation (RAG), which has attracted attention as a method for integrating recent information into large-scale language models (LLMs) or building domain-specific models. RAG utilizes multiple embedding models, but their heterogeneous characteristics lead to discrepancies in the similarity calculation results and the quality of the LLM responses. To address this issue, we propose Mixture-Embedding RAG and Confident RAG. Mixture-Embedding RAG integrates the retrieval results of multiple embedding models but fails to improve performance over conventional RAG. On the other hand, Confident RAG generates responses multiple times using multiple embedding models and selects the response with the highest confidence. This approach improves performance by approximately 10% and 5% over conventional LLM and RAG, respectively. Consistent results across various LLMs and embedding models demonstrate that Confident RAG is an efficient plug-and-play approach applicable to a wide range of fields.