To create innovative ideas, it is important for designers to monitor thought patterns by reflecting upon their thought structure and then control thought. In this study, we visualized the inference process, which includes deduction, induction, and abduction, as well as the associative process. Subsequently, by connecting them radially along the flow of thought, we employed a method of visualizing the inference process of designers on a two-dimensional plane. We conducted an experiment to visualize a part of the thought of designer using the “inference mapping method.” Consequently, we found out that different cognitive biases occurred in designers' deductive, inductive, abductive, and associative thinking processes. From the technical viewpoint of cognitive science, we studied the phenomena and clarified the structure of bias in each thought process. Finally, we proposed a way to visualize cognitive biases and to consciously eliminate them when designers engage in the creative process.