PROBLEM TO BE SOLVED: To provide a filter excelling in decaffeination efficiency and work efficiency.SOLUTION: The filter has a filter matrix containing activated clay powder or acid clay powder with an average particle diameter of 0.1-100 &mum in a range of 20-80 mass% based on the mass of the filter matrix, and ultrahigh molecular weight polyethylene powder or high molecular weight polyethylene powder in a range of 80-20 mass% based on the mass of the filter matrix.