To reduce the manual work processes, improve the working efficiency, improve the versatility of a raw material and expand the use of a finished product.

A stocking-shaped pattern boot 4 composed of rib stitched slip-on section 2 and a knitted fabric main body 3 is fitted on a solid last 1, and the solid last 1 on which the pattern boot 4 is fitted is immersed in a latex solution A by a given number of times, and a sole section 7 is fixed on the pattern boot 4, and then the pattern boot 4 is removed from the solid last 1, and the pattern boot 4 is dried and a rubber content in the latest solution A is vulcanized to manufacture a pair of work boots.