A nozzle for the gunning of monolithic refractories, being provided with a liquid adding mechanism (6), characterized in that an air or air-liquid mix feeding portion (4) having an inlet (4a) and a tube protecting pipe (3) are arranged in order following the liquid adding mechanism (6), a flange portion (1a) of a flexible inner layer tube (1) is anchored on the liquid adding mechanism side of said feeding portion (4) while another flange portion (2a) of a flexible outer layer tube (2) is anchored on the side of an outlet (10) of the feeding portion (4) thereby to insert the inner layer tube (1) into the outer layer tube (2), and an annular dead space (11) communicating with the inlet (4a) is formed between the inner layer flange portion (1a) and said outer flange portion (2a).