PURPOSE: To provide a creaky sound preventive surface treatment agent to prevent a creaky sound generated when interior trim parts rub against each other by vibration at automobile traveling time.

CONSTITUTION: A creaky sound preventive function is provided in such a way that a first layer 6 by containing spherical urethane particles 4 and/or rubber type particulates whose average particle diameter is in a range of 5 to 50μm by a range of 1 to 70wt% in resin for acrylic - vinyl chloride type paint is arranged on a surface of an interior trim skin material for an automobile and a second layer 7 by containing silica particles 5 whose average particle diameter is 1 to 8μm by a range of 1 to 30wt% as a glazing agent in resin for acrylic - vinyl chloride type paint is arranged on the first layer 6.