Abstract: A silylation method wherein a resist coating applied on a substrate is reacted with an organic silane compound under the irradiation of a deep ultraviolet ray to render regions of the resist coating durable to oxidative ion etching, whereby a fine pattern is formed. The resist coating includes a layer of an active polymer which is reactive with an organic silane compound under the irradiation of a deep ultraviolet ray to be combined with silyl groups, and a layer of an inert polymer which is not reactive with an organic silicone compound under the irradiation of a deep ultraviolet ray. A desired pattern is formed with the resist coating by ordinary lithographic technique, and then the active polymer layer of the pattern is allowed to contact with an organic silane compound while being irradiated with a deep ultraviolet ray to introduce silyl groups into the active polymer layer of the pattern so as to form masking regions durable to oxidative ion etching.