Disclosed herein is a separation column comprising a porous block covered with a coating wherein space-free adhesion is attainable therebetween by low temperature process without releasing octadecylsilyl bases and others from the porous block. A monolith rod 1 is covered with a metal or resin coating 2. Then, the monolith rod 1 covered by the coating 2 is further covered with a rod retainer 3 made of a low melting point metal (melting point 100-200 degrees C.) to form a column body 19. Since the rod retainer 3 is formed by pressure molding at low temperature (100-200 degrees C.). It is therefore possible to absorb the surface irregularities of the monolith rod 1 by the coating 2 while octadecylsilyl bases and others from are released when the retainer 3 is formed. This allows the potential separation ability of the porous block to be brought out maximally.