A ceramic substrate for a thin film electronic component, a production method thereof, and a thin film electronic component using the ceramic substrate A first substrate (1) includes a dense glass-ceramic mixed layer (33) containing glass in its surface portion. A second substrate is prepared such that a glass layer (32) formed on a surface of a substrate base portion (2) is subjected to a heat-pressure treatment so as to form or rather partly change the glass portion (32) into a dense glass-ceramic mixed layer (33) in which glass is dispersed into a surface portion of the substrate base portion (2). A surface of the dense glass-ceramic mixed layer (33) is then subjected to grinding or rather polishing to flatten and expose a surface of the dense glass-ceramic mixed layer (32). A third substrate includes a substrate base portion (2) having a dense glass-ceramic mixed layer (33) containing glass on a surface portion in one face side, and a wiring pattern (21) formed inside the substrate base portion (2). In the wiring pattern (21), one end thereof is exposed on or from a surface of the dense glass-ceramic mixed layer (33) and the other end is exposed on or from another surface of the substrate.