The objects of the invention are to provide a sheet chuck that enables a flexible sheet substrate to come in uniform contact with a stamp, and a microcontact printing process of using that sheet chuck to form a high-precision pattern. The sheet chuck of the invention comprises a base having a sheet substrate carrying surface defined by an upper surface thereof, a suck-in/suck-out port positioned on the carrying surface, and a holder positioned on the carrying surface in such a way as to surround the suck-in/suck-out port, and the suck-in/suck-out port is an area capable of sucking in or sucking out gas.