Abstract: To provide a surface treatment method for smoothing the surface of a ceramic thermal spray coating, and a ceramic thermal spray coating subjected to the surface smoothing treatment. A surface treatment method for a ceramic thermal spray coating, which comprises jetting a slurry containing a liquid having a viscosity at a temperature of 20° C. of 10 mPa/s or lower and a powder medium having a polyhedral structure and having a median diameter (D50) of from 1 to 50 ?m with a content of the powder medium of from 1 to 50 vol %, against a surface of a ceramic thermal spray coating, using a compressed gas under a pressure of from 0.01 to 1.0 MPa, to smooth the surface of the ceramic thermal spray coating.