Method for producing Ddr type zeolite seed crystal and a method for manufacturing the same, and ddr zeolite membrane

When used as a seed crystal for forming the DDR type zeolite membrane on the surface of the porous support, to provide a DDR type zeolite seed crystal can be suppressed surplus DDR type zeolite crystals may occur. Mean a particle diameter of 0.05～1.5Myuemu, particles of 1 to 3 "aspect ratio is a value obtained by dividing the maximum Feret diameter minimum Feret diameter", containing 90% or more, the square of the aspect ratio DDR type zeolite seed crystal coefficient of variation is 0.3 or less.