To provide a means for efficiently forming a tile base having an orthorhombic parallelogram shape such as a rhombus, by wet forming.

The tile base, extruded from an extrusion molding machine, is transversely cut to form a rectangular cut base, thereafter the cut base is oriented in the oblique direction by an orientation plate, which projects in the oblique direction on a transportation passage with good sliding property, then the orientation plate is made to advance to the intersecting direction to the transportation passage to push out the cut base in the side direction of the transportation passage, and the cut base is push-cut by a plurality of cutters which are fixed to the pushing out position in the vertical direction in the determined mutual distance.