PURPOSE: To provide an envelope capable of using the same through the resealing thereof by a method wherein an enclosure is inserted in an envelope where a cohesive layer is formed on a top portion of the inner surface of a sealing piece with which a peeling paper is pasted and further by a method wherein the sealing piece is folded therein and a portion near the enclosure inlet is sealed with an adhesive. CONSTITUTION: An envelope 1 is formed by having an upper envelope sheet 2 and lower envelope sheet 3 adhered by three side edges wherein a side edge is opened as an enclosure inlet 5 and a sealing piece 7 is extended to the upper envelope sheet 2 via a folding portion 6. A cohesive 8 used to reseal the envelope is coated in a beltlike form on a top portion inside the sealing piece 7 and a peeling sheet 9 is removably adhered thereon. An enclosure 10 is inserted from the enclosure inlet 5. An adhesive 12 is coated in a beltlike form near the enclosure inlet 5 of the lower envelope sheet 3 facing the folding portion 6 at which the sealing piece 7 is folded therein. The adhesive 12 is used for a first sealing and has preferably such adhesive intensity that an envelope can be opened when peeling off the sealing piece 7 from the lower envelope sheet 3. An envelope 21 which can be resealed is completed after folding the sealing piece 7 inside the folding portion 6, and coating the portion near the enclosure inlet 5 with the adhesive 12.