PURPOSE: To shorten pitch intervals between cutting channels and to prevent a flooring from damage during the construction or in conveyance even if the depth of the cutting channels is cut deep.

CONSTITUTION: A fitting projection 3 is formed in one side end section of a wood section 2 of a flooring 1 and, a fitting recess section 4 capable of fitting to the fitting projection 3 is formed in the other side end section. Cutting channels 5 from the side end section of the fitting projection 3 side to the side end section of the fitting recess section 4 side are cut upward from the lower side and are formed. During the conveyance or construction of the soundproof flooring 1, a soundproof flooring form keeping core 6 is fitted over the approximate overall length of the fitting recess section 4 of the soundproof flooring 1 in a detachable manner, and the form of the soundproof flooring 1 is kept.