To apply paint having a strong thixotropy stably and appropriately by restraining variations in thickness of a coating film and coating defects.

A shearing treating means is provided inside a die head 101 that renders a prescribed shearing action to paints. Inside a column-like space 115 formed in a main die body 111, an inner wall face 115a of the space and a rotary axis 116 are arranged with a predetermined gap to form a ring-like circulation space 124. The ring-like circulation space 124 comprises part of a communication channel 114 which communicates a space between a paint supply port 112 and a slit 113a for coating. A rotary axis 116 provides a shearing action against the paint flowing through the ring-like circulation space 124 by rotating at a predetermined revolutionary speed in the arrow A direction, thereby destroying structural viscosity of the paint. This constitution of the paint allows coating in a condition with its viscosity lowered.