PROBLEM TO BE SOLVED: To obtain a long mat for raising and transplanting seedlings to stably raise and transplant the seedlings without causing the generation of a miss-planted point, and enabling improved labor save, by using a biodegradable material having rigidity, etc., which do not permit the elongation of the long mat by an operation for scraping the seedlings, etc. SOLUTION: This long mat for raising and transplanting the seedlings of a plant such as rice is rolled, after the seedlings are raised, and is subjected to operations for dividedly scratching the seedlings, when the seedlings are transplanted. Therein, the mat is made from a biodegradable material, such as a plant raw material comprising chaff, peat moss or barks, which has a rigidity not permitting the elongation of the mat on the scratching operation, has a prescribed specific gravity enabling the transplantation of the seedlings from their root portions on the transplantation of the seedlings, and has a tensile strength of >=1.0 kg and a unit weight of 200-500 g per unit area (28 cm×58 cm). It is preferable to add agrochemicals and/or fertilizers to the mat or apply the agrochemicals and/or the fertilizers to the mat during the raising of the seedlings or just before the transplantation of the seedlings.
