PURPOSE: To surely prevent a positional shift of a gutter cushioning material at the time of placing a concrete and to surely expose the gutter cushioning material even at both ends thereof.

CONSTITUTION: Projected parts 13 are erected on a side edge and both end edges of a cover receiving surface forming part 12 for forming a cover receiving surface of a concrete gutter groove block so as to surround the full peripheral surface of a gutter cushioning material 40 together with a groove surface forming part 11 for forming a groove surface of the concrete gutter groove block. A relief part 14 is recessed in the projected part 13 and fitted with a joint forming part 13 of an end face plate 30 for forming a joint of an end face of the concrete gutter groove block.