This paper presents a deep learning model for predicting the mechanical properties of composite materials. To address the high computational cost of conventional finite element analysis (FE), we developed a model using a convolutional neural network (CNN) to predict the elastic modulus and yield strength of composite materials. Specifically, to overcome the limitations of previous studies, which typically employ a simple neural network structure (T30772), consider only elastic properties, and lack transparency, we applied explainable AI (XAI) techniques to enhance the interpretation and reliability of the model's prediction results. We trained the CNN using a dataset generated from transverse tensile tests and achieved higher accuracy than the ResNet-34 model. We validated the model's reliability by demonstrating that the CNN utilizes important geometric features that influence composite material behavior using SHAP and Integrated Gradients techniques.