An object of the present invention is to provide a process for producing microspheres that are solid microparticles or liquid microparticles for use as an emulsion employed in the food industry, production of medicine and cosmetic etc. or an emulsion for DDS (drug delivery system). The object is attained by a process for producing a microsphere including: separating a disperse phase from a continuous phase by a substrate 1 having a through-hole 7; and extruding the disperse phase into the continuous phase through the through-hole 7, in which the substrate having the through-hole 7 with a width of 0.5 to 500 μm, a depth of 10 μm to 6000 μm and a ratio of the width to the depth of the through-hole 7 of 1 to 1/30 is a metal substrate.