A grain flour includes milled grains of at least one grain selected from the group consisting of barley and oat. In the grain flour, the average grain diameter is in the range of 40-100 μm. The content of grains having a grain diameter less than 20 μm is not greater than 20 mass %, the content of grains having a grain diameter in the range of 20-100 μm is in the range of 20-60 mass %, the content of grains having a grain diameter greater than 100 μm and not greater than 500 μm is in the range of 20-60 mass %, and the content of grains having a grain diameter greater than 500 μm is not greater than 5%. An application food using the grain flour is produced from a starting material which contains at least 5% of the grain flour. A method for producing the grain flour is also provided.
