Transistor manufacturing method and transistor

A transistor manufacturing method comprising:

• forming a first insulator layer on a substrate on which a source electrode, a drain electrode, and a semiconductor layer in contact with surfaces of the source electrode and the drain electrode are formed so as to cover the semiconductor layer;
• forming a second insulator layer so as to cover the first insulator layer;
• forming a plating base film on at least part of a surface of the second insulator layer;
• and
• after depositing a metal which is an electroless plating catalyst on a surface of the plating base film, forming a gate electrode on the surface of the plating base film by electroless plating, wherein
• the forming of the plating base film is performed by applying a liquid substance which is a formation material of the plating base film to the surface of the second insulator layer,
• a formation material of the first insulator layer is a resin including no polar group, and
• the second insulator layer has a higher lyophilic property with respect to the liquid substance than the first insulator layer.