A contour of an outer diameter dimension of a dried ceramic honeycomb body is measured in a first measuring portion Q1 and a second measuring portion Q2 of the surface of an outer wall of the dried ceramic honeycomb body; a total of absolute values of differences between respective values of four contours C1x, C1y, C2x and C1y measured at a first measurement point P1x and a second measurement point P1y of the first measuring portion Q1 and a third measurement point P2x and a fourth measurement point P2y of the second measuring portion Q2 is obtained; and one end surface and the other end surface are subjected to finishing step in a state where four measurement points of the outer wall, at which the total of the absolute values is minimum, are fixed by a first fixture and a second fixture.