Method of producing flow passage device and flow passage device

A method of producing a flow passage device that includes a first base body having a first hole and a second base body having a second hole connected to the first hole to form a flow passage, the method comprising the steps of:

• preparing the first base body that has a first portion around the first hole, the first portion having a specified shape for holding an adhesive;
• preparing the second base body that has a high-wettability surface around the second hole with a low-wettability surface disposed proximate the high-wettability surface, at least part of the high-wettability surface being patterned to have a shape that matches at least part of the specified shape of the first portion of the first base body;
• holding the adhesive in the first portion for holding the adhesive;
• and
• forming the flow passage by causing the first base body and the second base body to oppose each other with positions of the first hole and the second hole aligned with each other by aligning the first portion for holding the adhesive with the high-wettability surface in a specified form.